Responding to a Coffee Spill on a Laptop | Learn Japanese in English

Japanese lesson set in a contemporary Tokyo everyday setting: In daily life, two adults respond to coffee spilled on a laptop by turning it off, checking backups, and seeking repair advice..

EN → JA / Level: B1

10 minutes free every day

Continue audio lessons in the app

Word explanations appear automatically in sync with the audio.

No login required · synced translations · playback with the screen locked

Choose your learning language and open this lesson in the app.

Kotobridge app audio lesson and word notes

About This Lesson

Use Responding to a Coffee Spill on a Laptop to practice Japanese conversation, pronunciation, vocabulary, grammar, and quizzes.

Dialogue

A

ノートパソコンの近くにコーヒーをこぼして、キーボードの下に少し液体が入りました。

NOH-toh pah-soh-KOHN noh CHEE-kah-koo nee KOH-hee oh koh-BOH-shee-teh, KEE-boh-doh noh SHEE-tah nee soo-KOH-shee eh-kee-TAI gah hah-ee-ree-mah-SHTAH. I spilled coffee near my laptop, and some liquid went under the keyboard.
B

すぐに電源プラグを抜いて、まだ動いているなら電源を切ってください。

soo-GOO-nee den-gen POO-rah-goo oh noo-EE-teh, mah-DAH oo-GOH-ee-teh-EE-roo nah-rah den-gen oh kee-TEH koo-dah-SAI. Unplug it immediately and turn it off if it is still running.
A

ドライヤーで乾かしてみたほうがいいですか。

doh-RAI-yah deh kah-rah-KAH-shee-teh mee-tah HOO gah EE dess-kah. Should I try to dry it with a hair dryer?
B

熱でさらに損傷することがあります。技術者に確認してもらいましょう。

NEH-tsu deh sah-rah-nee son-SHOH soo-roo KOH-toh gah ah-ree-mahss. gee-TSOO-shah nee kah-koo-NEEN she-teh moh-RAI-mah-SHOH. Heat can cause more damage. Let a technician check it.
A

その中にプロジェクトのファイルが入っているので心配です。

soh-noh nah-kah nee puh-roh-JEH-koo-toh noh FAI-roo gah hah-TEH-ee-roo noh-deh sheen-PAI dess. I am worried because my project files are on it.
B

ノートパソコンをもう一度触る前に、別の端末からクラウドのバックアップを確認してください。

NOH-toh pah-soh-KOHN oh moh-EE-chee-doh sah-WAH-roo mah-eh nee, beh-TSOO noh tahn-MAHT-soo kah-rah KOO-rah-OO-doh noh BAH-koo-AHP oh kah-koo-NEEN she-teh koo-dah-SAI. Check your cloud backup from another device before you touch the laptop again.
A

ほとんどのファイルはすでに同期されていました。

hoh-TOHN-doh noh FAI-roo wah soo-deh-NEE DOH-kee sah-reh-teh ee-mah-SHTAH. Most of the files were already synced.
B

ノートパソコンの電源は切ったままにして、すぐに起動しようとしないでください。

NOH-toh pah-soh-KOHN noh den-gen wah kee-TAH mah-MAH nee she-teh, soo-GOO-nee kee-DOH she-YOH toh she-NAI deh koo-dah-SAI. Keep the laptop off, and do not try to start it too soon.
A

技術者のところに持って行って、次に何をすればよいか聞きます。

gee-TSOO-shah noh toh-KOH-roh nee moh-TEH ee-TEH, TSOO-ghee nee nah-nee oh soo-REH-bah yoh-EE kah KEE-kee-mahss. I will take it to a technician and ask about the next step.
B

技術者なら、損傷を悪化させずに確認できます。

gee-TSOO-shah nah-rah, son-SHOH oh ah-KAH-sah-seh-zoo nee kah-koo-NEEN deh-kee-mahss. A technician can check it without making the damage worse.

Sentence explanations

  1. ノートパソコンの近くにコーヒーをこぼして、キーボードの下に少し液体が入りました。

    I spilled coffee near my laptop, and some liquid went under the keyboard.

    ノートパソコン
    laptop
    近くに
    near
    コーヒー
    coffee
    こぼして
    spilled
    キーボード
    keyboard
    下に
    under
    少し
    a little; some
    液体
    liquid
    入りました
    went in
    More detail

    ノートパソコン means “laptop.” It is a compound noun: ノートパソコンの近くに means “near the laptop.” The の links the noun to the following location expression. 近くに means “near” here. 近く is a location noun meaning “the vicinity,” and に marks the place where the spilling occurred. A reusable pattern is Nの近くに (“near N”). Example: 駅の近くに住んでいます。—“I live near the station.” コーヒー means “coffee.” In this sentence it is the thing affected by the action, marked by を. The fixed translation identifies the omitted actor as “I,” but Japanese does not state that actor in this sentence. こぼして is the connective て-form of the transitive verb こぼす, “to spill.” The form こぼして connects this action to the following clause: “spilled coffee and …” or, naturally here, “I spilled coffee near my laptop, and …” Do not confuse it with こぼれる, “to spill over / be spilled” as an intransitive verb. Example: 水をこぼしました。—“I spilled water.” キーボード means “keyboard.” In キーボードの下に, の links it to 下, giving “under the keyboard.” 下に means “under” here. 下 means “the lower part” or “below,” and に marks the location into which the liquid entered. The pattern Nの下に means “under N.” Example: 机の下にかばんがあります。—“There is a bag under the desk.” 少し means “some” or “a little” here. It indicates a small amount of liquid; it does not itself specify an exact measurement. It modifies 液体 in the following phrase. 液体 means “liquid.” It is the grammatical subject of 入りました, marked by が. Thus the sentence says that some liquid entered, without specifying a different kind of liquid beyond the translation’s context. 入りました is the polite past form of 入る, “to enter” or “go in.” The past ending ました presents the entering as completed, and が marks what entered: 液体が入りました means “liquid went in.” Here, the destination is marked by に: キーボードの下に液体が入りました means “liquid went under the keyboard.” Together, ノートパソコンの近くにコーヒーをこぼして gives “I spilled coffee near my laptop,” with the actor understood from the fixed translation. キーボードの下に少し液体が入りました gives “some liquid went under the keyboard.” The complete meaning is: “I spilled coffee near my laptop, and some liquid went under the keyboard.”

  2. すぐに電源プラグを抜いて、まだ動いているなら電源を切ってください。

    Unplug it immediately and turn it off if it is still running.

    すぐに
    immediately
    電源プラグ
    power plug
    抜いて
    unplug, and then
    まだ
    still
    動いている
    running
    なら
    if
    電源
    power
    切ってください
    please turn off
    More detail

    すぐに means “immediately” and modifies the actions that follow. It is a useful adverb for an action that should happen without delay. For example, すぐに来てください。 means “Please come immediately.” 電源プラグ is “power plug.” 電源 means electrical power or a power supply, and プラグ means plug. In this sentence, the compound identifies the plug used to supply power; it is the object of the first action. 抜いて is the て-form of 抜く, “to pull out” or “to unplug.” Here it means “unplug,” and the て-form connects this action to the next instruction: “unplug it, and then …” The observed form is not an imperative by itself; the connected sequence and the following 切ってください make the overall instruction polite. For example, コンセントからコードを抜いてください。 means “Please unplug the cord from the outlet.” まだ means “still” here. It indicates that the condition may continue to hold at the relevant time. It is not the same as もう, which commonly means “already” or “any longer,” depending on the construction. 動いている means “be running” here. 動いている consists of 動く, “to move” or “to operate,” in its て-form 動いて plus いる. With an activity such as a machine operating, this form describes an ongoing state: “is running.” For example, 機械が動いている。 means “The machine is running.” なら marks a condition based on the situation just described: “if it is still running” or “if that is the case.” The pattern [condition] なら、[action] can introduce advice or an instruction. Here, まだ動いているなら is the complete conditional phrase; なら does not itself identify what the omitted subject refers to. 電源 means “power” or “power supply.” In 電源を切る, it forms the common expression “to turn off the power.” The particle を marks 電源 as the object of 切る; the noun itself does not mean “turn off.” 切ってください is the polite request form of 切る, “to cut” or, with power or a device, “to turn off.” 切って is its て-form, followed by ください (“please”), so the expression means “please turn off.” For example, 電気を切ってください。 means “Please turn off the light/electricity,” with the exact object determined by context. Together, すぐに電源プラグを抜いて gives “unplug it immediately,” with the omitted object understood from the situation and the fixed translation. まだ動いているなら adds the condition “if it is still running.” Finally, 電源を切ってください gives the polite instruction “please turn it off.” The whole utterance therefore means: “Unplug it immediately and turn it off if it is still running.”

  3. ドライヤーで乾かしてみたほうがいいですか。

    Should I try to dry it with a hair dryer?

    ドライヤー
    hair dryer
    乾かしてみたほうがいいですか
    should I try drying it?
    More detail

    ドライヤー means “hair dryer.” It is a loanword noun. In this sentence, で follows it and marks the tool or means used for an action: ドライヤーで means “with a hair dryer.” 乾かしてみたほうがいいですか asks whether trying to dry something would be advisable. The lexical verb is 乾かす, “to dry something”; it is transitive, so the thing being dried is understood rather than stated in this sentence. The form 乾かして is its connective て-form. 〜てみる means “try doing ~.” Here, 乾かしてみた uses the past form みた inside that construction, referring to the proposed attempt, not simply to a completed drying action. 〜たほうがいい presents an action as the better or advisable choice. With ですか, the whole expression becomes a polite question: “Would it be better for me to try…?” Together, ドライヤーで identifies the tool, and 乾かしてみたほうがいいですか asks whether trying to dry the understood object with it is advisable. Thus the complete meaning is: “Should I try to dry it with a hair dryer?”

  4. 熱でさらに損傷することがあります。技術者に確認してもらいましょう。

    Heat can cause more damage. Let a technician check it.

    熱
    heat
    さらに
    further; more
    損傷する
    be damaged; sustain damage
    ことがあります
    can happen
    技術者
    technician
    確認してもらいましょう
    let someone check it
    More detail

    熱 means “heat” here. The particle で after it marks the cause or means by which something happens: 熱で = “because of heat” or “from heat.” Example: 水で洗います。 — “I wash it with water.” さらに adds a further increase: “more,” “further,” or “even more.” It indicates damage beyond an earlier or existing amount. Example: さらに悪くなりました。 — “It got even worse.” 損傷する means “to become damaged” or “to sustain damage.” The base form is 損傷する; 損傷し is its stem before ます, and 損傷することがあります is the relevant pattern here. This verb describes damage rather than the act of damaging something. Example: 部品が損傷しました。 — “The component was damaged.” ことがあります follows a verb in its plain form and expresses that there are cases in which something happens, often translated as “can” or “sometimes.” Here, 損傷することがあります means “can sustain damage”; it does not assert that the damage definitely occurs. Example: この機械は止まることがあります。 — “This machine can stop sometimes.” Together, 熱でさらに損傷することがあります means “Heat can cause more damage.” The Japanese does not state an explicit subject; the thing being discussed is understood from the situation and from the fixed translation as the thing that may become more damaged. 技術者 means “technician.” The noun identifies the person who will be asked to perform the check. Example: 技術者に相談します。 — “I consult a technician.” 確認してもらいましょう combines 確認する (“to check” or “confirm”), its て-form 確認して, and もらう (“to receive” a person’s action as a favor). The pattern 人に〜てもらう means “have someone do ~ for you” or “ask someone to do ~.” The ending ましょう presents a suggestion, so the whole form means “let’s have [someone] check it” or “let a technician check it.” The object is omitted in Japanese and is understood here as the item under discussion, matching “it” in the translation. Example: 専門家に見てもらいましょう。 — “Let’s have a specialist take a look at it.” The complete utterance first warns that heat may cause further damage, then suggests arranging for a technician to check the item. ましょう makes the second sentence a cooperative proposal rather than a bare command.

  5. その中にプロジェクトのファイルが入っているので心配です。

    I am worried because my project files are on it.

    その中に
    inside it
    プロジェクト
    project
    ファイル
    file
    入っている
    be inside; be contained
    ので
    because
    心配です
    am worried
    More detail

    その中に means “inside it” here. その points to an already identified object, and 中 means “inside” or “interior.” The particle に marks the place where something exists. Japanese demonstratives such as その do not by themselves identify the object; the fixed translation supplies the intended reference as “it.” Example: 箱の中に本があります。 — “There is a book inside the box.” The same location pattern is 場所に物がある (“an object is in a place”). プロジェクト is the loanword “project.” It is a noun and can combine directly with another noun: プロジェクトのファイル means “the project’s file(s),” with の linking the two nouns. ファイル means “file.” Japanese does not obligatorily mark singular versus plural on this noun, so the form can mean “a file” or “files”; the fixed translation selects “files” here. プロジェクトのファイル therefore means “the project files.” 入っている comes from the intransitive verb 入る (“enter; go in”). Its て-form is 入って, followed by いる. In this sentence, 入っている describes the resulting state: the files are contained inside the object. The verb 入れる is different: it is transitive and means “put something in,” so it requires a person or other agent who puts something somewhere. Example: かばんに鍵が入っています。 — “The keys are in the bag.” This uses the same pattern: place に object が 入っている. ので connects the preceding situation with its consequence and means “because” or “since.” Thus プロジェクトのファイルが入っているので means “because the project files are inside it.” The clause before ので gives the reason, while the following clause gives the speaker’s response. Compared with から, ので is another common reason-linking form and often presents the reason in a relatively explanatory, less forceful way. 心配です means “am worried” or “am concerned.” 心配 is a noun that can function as a な-type descriptive predicate; です makes the predicate polite. The fixed translation identifies the unspoken experiencer as “I,” although Japanese does not state that subject in this sentence. 心配する is the related verb “to worry,” while 心配です describes the state of being concerned. Together, その中にプロジェクトのファイルが入っている says that the project files are inside the already identified object. Adding ので makes that fact the reason, and 心配です states the speaker’s concern: “I am worried because my project files are on it.”

  6. ノートパソコンをもう一度触る前に、別の端末からクラウドのバックアップを確認してください。

    Check your cloud backup from another device before you touch the laptop again.

    ノートパソコン
    laptop
    もう一度
    again; one more time
    触る
    touch
    前に
    before
    別の
    another; different
    端末
    device; terminal
    クラウド
    cloud
    バックアップ
    backup
    確認してください
    please check
    More detail

    ノートパソコン means “laptop” here. It is a compound noun: ノートパソコン is the device being touched, marked by を in ノートパソコンを. A useful example is ノートパソコンを使います。 — “I use a laptop.” もう一度 means “again” or “one more time.” It indicates that the touching has happened before; it does not by itself specify how many earlier times. もう一度確認してください。 means “Please check it again.” 触る is the dictionary form of the verb meaning “to touch.” In this sentence it takes the object ノートパソコンを. The form 触る appears before 前に because Japanese uses the plain form before this temporal expression: Vる前に means “before doing V.” The polite request form of this verb is 触ってください, “please touch,” but that is not the form used here; the request in the utterance is instead directed at 確認する. 前に means “before.” Here it follows the clause ノートパソコンをもう一度触る, producing “before touching the laptop again.” The noun pattern Nの前に also means “before N,” while the verb pattern Vる前に means “before doing V.” Example: 寝る前に歯を磨きます。 — “I brush my teeth before going to bed.” 別の means “another” or “different” and modifies the following noun 端末. It presents that device as different from the laptop mentioned in the earlier part; the word itself does not identify the device’s exact type. 別の方法 means “another method.” 端末 means “device” in this context. It can refer to a computing or electronic terminal/device, and 別の端末から marks it as the source from which the checking is done. The particle から commonly marks a starting point or source, including a device or location: スマートフォンから送ります。 — “I will send it from a smartphone.” クラウド is “the cloud,” referring here to cloud-based storage or service infrastructure. クラウドのバックアップ is a noun phrase in which の links クラウド to バックアップ: “cloud backup.” バックアップ means “backup,” the stored copy or backup data being checked. It is the object of 確認してください, so the full object phrase is クラウドのバックアップを. Example: バックアップを作成します。 — “I create a backup.” 確認してください means “please check” or “please verify.” 確認する is the dictionary form of the verb “to check/confirm”; 確認してください consists of its て-form, 確認して, plus ください, a polite request pattern. The object being checked is marked by を, and the source is marked by から: 別の端末からバックアップを確認してください means “please check the backup from another device.” The sentence first gives the time condition: ノートパソコンをもう一度触る前に, “before touching the laptop again.” It then gives the requested action: 別の端末からクラウドのバックアップを確認してください, “please check the cloud backup from another device.” Together, the utterance means: “Check your cloud backup from another device before you touch the laptop again.”

  7. ほとんどのファイルはすでに同期されていました。

    Most of the files were already synced.

    ほとんどの
    most of
    ファイル
    file
    すでに
    already
    同期されていました
    was synced
    More detail

    ほとんどの means “most of” here. ほとんど expresses an amount close to all, and の links that quantity expression to the noun that follows: ほとんどの + noun. It does not by itself state an exact number. For example, ほとんどの学生が来ました。 means “Most of the students came.” ファイル is the noun “file,” written in katakana as a loanword. Japanese nouns generally do not change form for singular and plural, so this word can refer to one file or multiple files; the quantity expression ほとんどの gives the plural “most of the files” reading here. すでに means “already.” It indicates that the relevant situation was true by the time being discussed. It modifies the following predicate rather than being part of the noun phrase. For example, 彼はすでに帰りました。 means “He has already gone home.” 同期されていました describes the files as having been synced. Its useful base chain is 同期する “sync” → 同期される “be synced” (passive) → 同期されている “be in a synced state / have been synced” → polite past 同期されていました “was/were synced” or “had been synced.” The passive form focuses on the files receiving the action and does not identify who or what performed it. The ていました ending places that state in the past; Japanese does not add a plural ending to the verb, so the same form works with the plural meaning supplied by ほとんどのファイル. Together, ほとんどのファイル identifies most of the files, すでに says the result was already in place, and 同期されていました says they were in a synced state at the relevant past time. The complete meaning is “Most of the files were already synced.”

  8. ノートパソコンの電源は切ったままにして、すぐに起動しようとしないでください。

    Keep the laptop off, and do not try to start it too soon.

    ノートパソコン
    laptop
    電源
    power
    切ったままにして
    leave switched off
    すぐに
    right away
    起動しようとしないでください
    please do not try to start it
    More detail

    ノートパソコン means “laptop.” It is a commonly used compound noun for a portable computer. Example: ノートパソコンを使います。 — “I use a laptop.” 電源 means “power,” especially a device’s power supply or power state. In ノートパソコンの電源, の links it to the laptop: “the laptop’s power.” 電源を入れる means “turn on the power,” while 電源を切る means “turn off the power.” 切ったままにして contains the past form 切った of 切る, which means “cut” in other contexts but means “turn off” here. It is followed by ままにする, “leave something in a state.” Thus 切ったままにする means “leave it turned off.” The て form して links this request to the following request. Japanese verbs do not inflect for gender or number. すぐに means “right away” or “immediately.” It modifies the following action. Example: すぐに返事をしないでください。 — “Please do not reply immediately.” 起動しようとしないでください means “please do not try to start it.” 起動する is used for starting or booting a computer or other device. The form 起動しよう is the volitional form of 起動する; by itself it expresses “let’s start” or “I’ll start.” In the pattern 起動しようとする, the volitional form followed by とする means “try to start.” Here, 起動しようとしないでください uses the negative-request pattern 〜ないでください with that construction: “please do not try to start.” Together, ノートパソコンの電源は sets the laptop’s power as the topic, and 切ったままにして asks the listener to leave it switched off. すぐに起動しようとしないでください adds the request not to try to start it right away. The complete meaning is: “Keep the laptop off, and do not try to start it too soon.”

  9. 技術者のところに持って行って、次に何をすればよいか聞きます。

    I will take it to a technician and ask about the next step.

    技術者
    technician
    のところに
    to someone’s place
    持って行って
    take it there, and…
    次に
    next
    何をすればよいか
    what to do
    聞きます
    ask
    More detail

    技術者 means “technician.” It is a noun; the plural or singular is not marked in this form. In this sentence, the technician is the person whose place or presence is the destination. Example: 技術者に相談します。—“I consult a technician.” のところに marks a destination associated with someone: literally, “to someone’s place/where someone is.” Here, の links 技術者 to ところ, and に marks the destination. The phrase therefore gives the sense “to the technician,” without claiming a particular physical address. Example: 先生のところに行きます。—“I go to the teacher’s place.” 持って行って is the connective form of 持って行く, “to take something there/away.” 持って行く combines 持つ (“hold/carry”) with 行く (“go”), and its direction is away from the speaker or toward another destination. The object is omitted in the Japanese sentence; the fixed translation identifies it as “it,” understood from the situation. The -て form connects this action to the following action: “take it there and then…” Example: これを店に持って行きます。—“I will take this to the shop.” 次に is an adverb meaning “next” or “after that.” It sets the following action or information as the next step, rather than describing the order of the technician and the object. 何をすればよいか is an embedded question meaning “what one should do” or “what to do.” 何 means “what,” and を marks it as the object of する, “do.” すれば is the conditional form of する; with よい (“good/acceptable”), -ばよい expresses what is advisable or appropriate: “it is good if one does …,” naturally “one should ….” The final か marks the whole clause as an embedded question. This is different from a direct question such as 何をしますか。—“What will you do?” 聞きます is the polite nonpast form of 聞く. In this context, with an embedded question before it, it means “ask” rather than “listen/hear”: “ask what to do.” The nonpast polite form can refer to a planned or forthcoming action here. Example: 店員に営業時間を聞きます。—“I ask the shop employee about the opening hours.” Together, 技術者のところに持って行って gives “take it to the technician and then,” 次に何をすればよいか gives “what should be done next,” and 聞きます gives the polite planned action “I will ask.” The whole utterance therefore means: “I will take it to a technician and ask about the next step.”

  10. 技術者なら、損傷を悪化させずに確認できます。

    A technician can check it without making the damage worse.

    技術者
    technician
    損傷
    damage
    悪化させずに
    without making worse
    確認できます
    can check
    More detail

    技術者 means “technician.” It is a noun for a person with relevant technical expertise. Example: 技術者に相談します。— “I consult a technician.” 損傷 means “damage” or “damage to an object.” In this sentence, the following particle を marks 損傷 as what is affected by the action: 損傷を “the damage.” Example: 損傷を確認します。— “I check the damage.” 悪化させずに means “without making [it] worse.” The useful base pattern is 悪化する “become worse” → 悪化させる “make [something] worse” → 悪化させずに “without making [something] worse.” Here, 損傷を is the thing that must not be worsened. The ending ずに gives a formal written-style equivalent of ないで in this “without doing” pattern. Example: 状態を悪化させずに待ちます。— “I wait without making the condition worse.” 確認できます means “can check” or “can confirm.” 確認する is the basic verb “check/confirm,” and できます is its polite potential form, expressing that the action is possible: 確認する → 確認できる → 確認できます. Example: ここで内容を確認できます。— “You can check the contents here.” The opening 技術者なら frames a technician as the person for whom the following ability applies. The conditional/topic form なら can often be understood as “if it is a technician” or, in a general statement like this one, “for a technician.” The sequence 損傷を悪化させずに says that the checking is done without making the damage worse, and 確認できます states that this checking is possible. Together, the utterance means: “A technician can check it without making the damage worse.”

Grammar Points

〜てもらいましょう

技術者に確認してもらいましょう。

gee-TSOO-shah nee kah-koo-NEEN she-teh moh-RAI-mah-SHOH

Let's have a technician check it.

This pattern means asking or arranging for someone to do something for you. もらう expresses receiving that help.

〜ずに

損傷を悪化させずに、確認してもらいましょう。

son-SHOH oh ah-KAH-sah-seh-zoo nee, kah-koo-NEEN she-teh moh-RAI-mah-SHOH

Let's have it checked without making the damage worse.

〜ずに means “without doing.” It connects to a verb and describes an action that is avoided.

Japanese Vocabulary

キーボード noun
KEE-boh-doh keyboard
コーヒー noun
KOH-hee coffee
こぼして verb
koh-BOH-shee-teh spilling; spilled and
すぐに adv
soo-GOO-nee immediately
ドライヤー noun
doh-RAI-yah hair dryer
ノートパソコン noun
NOH-toh pah-soh-KOHN laptop
液体 noun
eh-kee-TAI liquid
近く noun
CHEE-kah-koo nearby; vicinity
電源プラグ noun
den-gen POO-rah-goo power plug
電源を切って phrase
den-gen oh kee-TEH turning it off; turn it off
動いている verb
oo-GOH-ee-teh-EE-roo running; operating
抜いて verb
noo-EE-teh unplugging; unplug and

Quiz

Spelling

Tap the letters to spell the word.

spilling; spilled and

Show Answerこぼして

coffee

Show Answerコーヒー

keyboard

Show Answerキーボード

power plug

Show Answer電源プラグ