When we break down the word 牙刷 (yá shuā), you'll see it's quite descriptive. 牙 (yá) literally means 'tooth' or 'teeth'. It's a very common component in words related to oral hygiene. For example, 牙医 (yáyī) is a dentist, and 牙膏 (yágāo) is toothpaste.
The second character, 刷 (shuā), means 'to brush'. You might encounter this character in other contexts where brushing is involved, like 刷鞋 (shuā xié) which means to brush shoes, or 刷碗 (shuā wǎn) meaning to wash dishes. So, literally, a 牙刷 is a 'tooth brush'.
It's a straightforward compound word that clearly conveys its meaning through its individual components. This is a common pattern in Chinese vocabulary, where combining simpler characters creates more complex meanings.
How Formal Is It?
"请使用口腔清洁器保持口腔卫生。"
"我每天早上用牙刷刷牙。"
"你有没有带你的刷子？"
"宝宝，用你的牙牙刷刷牙。"
"你的齿具哪儿去了？"
豆知識
The earliest known toothbrushes date back to 1498 in China, made from hog bristles attached to bamboo or bone handles.
難易度
Two common characters, easy to recognize.
Both characters are relatively simple to write.
Straightforward pronunciation with common tones.
Clear and distinct sounds.
次に学ぶべきこと
前提知識
次に学ぶ
上級
知っておくべき文法
Measure words are used with nouns to indicate quantity. For '牙刷' (toothbrush), a common measure word is '把' (bǎ), often used for objects with handles.
我要买一把牙刷。(Wǒ yào mǎi yī bǎ yáshuā.) - I want to buy a toothbrush.
To ask 'Do you have...?', you can use '你有...吗?' (Nǐ yǒu... ma?).
你有一把牙刷吗？(Nǐ yǒu yī bǎ yáshuā ma?) - Do you have a toothbrush?
To express possession, use '的' (de).
这是我的牙刷。(Zhè shì wǒ de yáshuā.) - This is my toothbrush.
To indicate the action of brushing teeth, you pair '刷' (shuā - to brush) with '牙' (yá - tooth). The object '牙刷' is the tool for this action.
我每天早上刷牙。(Wǒ měitiān zǎoshang shuāyá.) - I brush my teeth every morning.
When describing the color or material of a toothbrush, the adjective comes before the noun.
我喜欢蓝色的牙刷。(Wǒ xǐhuān lánsè de yáshuā.) - I like blue toothbrushes.
レベル別の例文
我需要买牙刷。
I need to buy a toothbrush.
你的牙刷在哪里？
Where is your toothbrush?
我每天用牙刷。
I use a toothbrush every day.
这支牙刷是新的。
This toothbrush is new.
请给我牙刷。
Please give me the toothbrush.
他有一支蓝色的牙刷。
He has a blue toothbrush.
牙刷在卫生间里。
The toothbrush is in the bathroom.
我没有牙刷。
I don't have a toothbrush.
よく使う組み合わせ
よく使うフレーズ
用牙刷刷牙
brush teeth with a toothbrush
我需要一个新的牙刷。
I need a new toothbrush.
你的牙刷在哪里？
Where is your toothbrush?
请给我拿一个牙刷。
Please hand me a toothbrush.
我忘了带牙刷。
I forgot to bring my toothbrush.
牙刷和牙膏。
Toothbrush and toothpaste.
他用牙刷清理了缝隙。
He cleaned the gap with a toothbrush.
这个牙刷很软。
This toothbrush is very soft.
你应该多久换一次牙刷？
How often should you change your toothbrush?
牙刷是日常用品。
A toothbrush is a daily necessity.
よく混同される語
This means 'toothpaste'. Often confused with '牙刷' due to being related oral hygiene items and similar sounding initial character '牙'.
This is the verb phrase 'to brush teeth'. While related, it describes the action, not the object 'toothbrush'.
This means 'comb'. Some learners might confuse the '刷' (brush) in '牙刷' with other brushing or combing tools, especially if they are not familiar with the specific usage.
間違えやすい
Many English speakers confuse '牙刷' (toothbrush) with '牙膏' (toothpaste) due to their similar sounds and related meanings. They also might incorrectly assume a direct translation of 'tooth' and 'brush' without understanding the specific Chinese word order.
牙刷 (yá shuā) specifically refers to the brush used to clean teeth, while 牙膏 (yá gāo) is the paste used with the brush. The '刷' in '牙刷' means 'to brush', clearly indicating the action and tool.
我需要买一支新<b>牙刷</b>。 (Wǒ xūyào mǎi yī zhī xīn <b>yáshuā</b>.) - I need to buy a new <b>toothbrush</b>.
暗記しよう
記憶術
Imagine a 'ya' (like 'yacht') with a 'shua' (like 'shoo-ah') sound when you brush your teeth with a new toothbrush. 'Ya shua' is for toothbrush.
視覚的連想
Picture a giant toothbrush in your mind, brushing a huge set of teeth. The bristles are made of the characters 牙 (yá) and 刷 (shuā).
Word Web
チャレンジ
Describe your morning routine in Chinese, making sure to include 牙刷 (yá shuā).
語源
Simplified Chinese characters
元の意味： 牙 (yá) means 'tooth' or 'teeth', and 刷 (shuā) means 'brush'.
Sino-Tibetan, Sinitic, Chinese文化的な背景
Brushing teeth is a universal practice, but the concept of a 'toothbrush' as a dedicated tool for oral hygiene has a long history in China. Traditional Chinese medicine emphasizes overall health, and oral hygiene is considered an important part of maintaining well-being. Even with modern dental products, the basic idea of 'tooth' + 'brush' remains central to the Chinese word.
実生活で練習する
実際の使用場面
At home, in the bathroom.
- 我需要一个新的牙刷。(Wǒ xūyào yī gè xīn de yáshuā.) - I need a new toothbrush.
- 你的牙刷在哪里？(Nǐ de yáshuā zài nǎlǐ?) - Where is your toothbrush?
- 请把牙刷递给我。(Qǐng bǎ yáshuā dì gěi wǒ.) - Please hand me the toothbrush.
When traveling, packing toiletries.
- 我忘了带牙刷。(Wǒ wàngle dài yáshuā.) - I forgot to bring my toothbrush.
- 这个酒店提供牙刷吗？(Zhège jiǔdiàn tígōng yáshuā ma?) - Does this hotel provide toothbrushes?
- 我需要买一个旅行牙刷。(Wǒ xūyào mǎi yī gè lǚxíng yáshuā.) - I need to buy a travel toothbrush.
At the store, buying hygiene products.
- 我想要一支软毛牙刷。(Wǒ xiǎng yào yī zhī ruǎnmáo yáshuā.) - I want a soft-bristled toothbrush.
- 这种牙刷多少钱？(Zhè zhǒng yáshuā duōshǎo qián?) - How much is this kind of toothbrush?
- 牙刷和牙膏在哪里？(Yáshuā hé yágāo zài nǎlǐ?) - Where are the toothbrushes and toothpaste?
Talking about daily routines.
- 你每天刷几次牙？(Nǐ měitiān shuā jǐ cì yá?) - How many times a day do you brush your teeth?
- 我早上和晚上都刷牙。(Wǒ zǎoshang hé wǎnshang dōu shuāyá.) - I brush my teeth in the morning and evening.
- 刷牙要用牙刷和牙膏。(Shuāyá yào yòng yáshuā hé yágāo.) - You need a toothbrush and toothpaste to brush your teeth.
Describing types of toothbrushes.
- 我喜欢电动牙刷。(Wǒ xǐhuan diàndòng yáshuā.) - I like electric toothbrushes.
- 儿童牙刷通常更小。(Értóng yáshuā tōngcháng gèng xiǎo.) - Children's toothbrushes are usually smaller.
- 硬毛牙刷对牙齿不好。(Yìngmáo yáshuā duì yáchǐ bù hǎo.) - Hard-bristled toothbrushes are not good for teeth.
会話のきっかけ
"你更喜欢用手动牙刷还是电动牙刷？(Nǐ gèng xǐhuan yòng shǒudòng yáshuā háishì diàndòng yáshuā?) - Do you prefer using a manual toothbrush or an electric one?"
"你多久换一次牙刷？(Nǐ duōjiǔ huàn yī cì yáshuā?) - How often do you change your toothbrush?"
"如果你去旅行，你会带自己的牙刷吗？(Rúguǒ nǐ qù lǚxíng, nǐ huì dài zìjǐ de yáshuā ma?) - If you travel, do you bring your own toothbrush?"
"你觉得什么样的牙刷最好用？(Nǐ juédé shénme yàng de yáshuā zuì hǎo yòng?) - What kind of toothbrush do you think is the best to use?"
"你有没有用过竹子做的牙刷？(Nǐ yǒu méiyǒu yòngguò zhúzi zuò de yáshuā?) - Have you ever used a bamboo toothbrush?"
日記のテーマ
描述你理想中的牙刷是什么样子的，为什么。(Miáoshù nǐ lǐxiǎng zhōng de yáshuā shì shénme yàngzi de, wèishénme.) - Describe what your ideal toothbrush looks like and why.
你有没有遇到过在旅行时忘记带牙刷的情况？你是怎么解决的？(Nǐ yǒu méiyǒu yù dào guò zài lǚxíng shí wàngjì dài yáshuā de qíngkuàng? Nǐ shì zěnme jiějué de?) - Have you ever forgotten your toothbrush while traveling? How did you solve it?
你觉得牙刷的颜色重要吗？你喜欢什么颜色的牙刷？(Nǐ juédé yáshuā de yánsè zhòngyào ma? Nǐ xǐhuan shénme yánsè de yáshuā?) - Do you think the color of a toothbrush is important? What color toothbrush do you like?
你对环保牙刷有什么看法？(Nǐ duì huánbǎo yáshuā yǒu shénme kànfǎ?) - What are your thoughts on eco-friendly toothbrushes?
写一篇小短文，描述你早上刷牙的完整过程。(Xiě yī piān xiǎo duǎnwén, miáoshù nǐ zǎoshang shuāyá de wánzhěng guòchéng.) - Write a short paragraph describing your complete morning teeth-brushing routine.
自分をテスト 66 問
我每天早上用___刷牙。(Wǒ měitiān zǎoshang yòng ___ shuāyá.)
The sentence means 'I brush my teeth every morning with a ___.' The correct word is 'toothbrush'.
请把你的___放在杯子里。(Qǐng bǎ nǐ de ___ fàng zài bēizi lǐ.)
The sentence means 'Please put your ___ in the cup.' The correct word is 'toothbrush'.
这把___是新的。(Zhè bǎ ___ shì xīn de.)
The sentence means 'This ___ is new.' The correct word is 'toothbrush'. Note that '把' (bǎ) is a measure word often used for objects with handles, like toothbrushes.
你旅行的时候记得带上你的___。(Nǐ lǚxíng de shíhou jìde dài shàng nǐ de ___.)
The sentence means 'When you travel, remember to bring your ___.' The correct word is 'toothbrush'.
我的___是蓝色的。(Wǒ de ___ shì lánsè de.)
The sentence means 'My ___ is blue.' The correct word is 'toothbrush'.
医生说我应该每天用___刷牙两次。(Yīshēng shuō wǒ yīnggāi měitiān yòng ___ shuāyá liǎng cì.)
The sentence means 'The doctor said I should brush my teeth twice a day with a ___.' The correct word is 'toothbrush'.
The sentence is about needing to buy a new item.
The sentence is asking about what kind of item someone uses.
The sentence describes a quality of the toothbrush.
Read this aloud:
我的牙刷在浴室。
Focus: yá shuā
あなたの回答：
Speech recognition is not supported in your browser. Try Chrome or Edge.
Read this aloud:
请给我拿一个牙刷。
Focus: yá shuā
あなたの回答：
Speech recognition is not supported in your browser. Try Chrome or Edge.
Read this aloud:
你喜欢电动牙刷吗？
Focus: diàn dòng yá shuā
あなたの回答：
Speech recognition is not supported in your browser. Try Chrome or Edge.
早上刷牙的时候，我发现我的___找不到了。
The sentence is about brushing teeth, and the missing item is something used for brushing teeth. '牙刷' (yáshuā) means toothbrush.
旅行时，别忘了带上你的___和牙膏。
The context mentions '牙膏' (yágāo - toothpaste), which suggests that '牙刷' (yáshuā - toothbrush) is the appropriate item to bring for personal hygiene when traveling.
医生建议我每三个月更换一次___。
Doctors usually recommend replacing your toothbrush every three months for better oral hygiene. '牙刷' (yáshuā) fits this context.
她买了一把新的电动___，刷牙更方便了。
The sentence describes buying a new 'electric ___' for easier brushing. '电动牙刷' (diàndòng yáshuā) means electric toothbrush.
酒店提供的免费洗漱用品里有___和牙膏。
Hotels typically provide a toothbrush and toothpaste as complimentary toiletries. '牙刷' (yáshuā) is a common item in hotel amenities.
小孩子应该用软毛的___。
For children, it's recommended to use a soft-bristled toothbrush to protect their gums and teeth. '软毛的牙刷' (ruǎnmáo de yáshuā) means soft-bristled toothbrush.
Choose the correct word to complete the sentence: 睡觉前我喜欢用新____。
The sentence means 'Before bed, I like to use a new toothbrush.' 牙刷 (yáshuā) is the correct word for toothbrush.
Which of these items is typically used for oral hygiene?
牙刷 (yáshuā) means toothbrush, which is used for oral hygiene. The other options are chopsticks, bowl, and spoon.
Fill in the blank: 你每天刷几次牙？用____刷牙。
The question asks 'How many times a day do you brush your teeth? Brush your teeth with a ____.' 牙刷 (yáshuā) is the correct tool for brushing teeth.
牙刷 (yáshuā) is an item you would typically find in a kitchen.
牙刷 (yáshuā) means toothbrush, which is usually found in a bathroom, not a kitchen.
A good way to keep your teeth clean is by using a 牙刷 (yáshuā) regularly.
牙刷 (yáshuā) means toothbrush, and using it regularly is essential for dental hygiene.
If you are traveling, you should pack your 牙刷 (yáshuā) in your suitcase.
牙刷 (yáshuā) means toothbrush, and it is a common item to pack when traveling.
What color is the toothbrush?
What is the speaker asking for?
What does the speaker do every morning?
Read this aloud:
我的牙刷坏了。
Focus: ya shua huai le
あなたの回答：
Speech recognition is not supported in your browser. Try Chrome or Edge.
Read this aloud:
你用什么牙刷？
Focus: ni yong shen me ya shua
あなたの回答：
Speech recognition is not supported in your browser. Try Chrome or Edge.
Read this aloud:
我需要买一个新的牙刷。
Focus: wo xu yao mai yi ge xin de ya shua
あなたの回答：
Speech recognition is not supported in your browser. Try Chrome or Edge.
她出差总是带上一把新的牙刷，以防万一。
这句话的含义是她为了预防万一，习惯性地带一把新牙刷，暗示她喜欢用新的。
这家酒店的洗漱用品很齐全，甚至连一次性牙刷都有。
“齐全”和“甚至连…都有”都表明这家酒店的洗漱用品考虑得很周到。
医生建议我每三个月更换一次牙刷，以保持口腔卫生。
“每三个月更换一次”是定期更换的一种表现，旨在强调保持口腔卫生。
刷牙时，使用硬毛牙刷能更有效地清洁牙齿。
通常医生会建议使用软毛牙刷，以避免损伤牙龈和牙釉质。
电动牙刷比普通牙刷能更好地去除牙菌斑。
许多研究表明，电动牙刷在去除牙菌斑方面通常比手动牙刷更有效。
牙刷用完后应立即盖上刷头盖，以防细菌滋生。
牙刷用完后应自然风干，盖上刷头盖反而可能创造潮湿环境，助长细菌滋生。
The speaker is talking about preferences between different types of toothbrushes.
The speaker is packing for a business trip.
This is a piece of advice from a dentist.
Read this aloud:
请描述一下你理想中的牙刷应该具备哪些功能和特点。
Focus: 理想中的 (lǐxiǎng zhōng de)
あなたの回答：
Speech recognition is not supported in your browser. Try Chrome or Edge.
Read this aloud:
你认为科技发展会如何改变未来的牙刷？
Focus: 科技发展 (kējì fāzhǎn)
あなたの回答：
Speech recognition is not supported in your browser. Try Chrome or Edge.
Read this aloud:
如果你要向朋友推荐一款牙刷，你会选择哪款，为什么？
Focus: 推荐 (tuījiàn)
あなたの回答：
Speech recognition is not supported in your browser. Try Chrome or Edge.
Imagine you are giving advice to a friend who is moving to China for the first time. Write a short paragraph about essential personal hygiene items they should bring or buy, making sure to include 'toothbrush' (牙刷) in your advice. Explain why it's important to have a good one.
Well written! Good try! Check the sample answer below.
Sample answer
当你搬到中国时，有些个人卫生用品是必不可少的。首先，一个好的牙刷非常重要，因为保持口腔清洁可以预防很多问题。虽然你可以在当地买到牙刷，但带一个你习惯的会更好。除了牙刷，你可能还需要考虑带上你喜欢的牙膏和洗发水。
Describe a situation where you had to borrow a toothbrush from someone, or lend one to someone. What was the context? How did you feel about it? Use '牙刷' in your description.
Well written! Good try! Check the sample answer below.
Sample answer
有一次旅行，我把牙刷忘在家里了。到了酒店才发现，真是太尴尬了。 Luckily, 我的朋友有多余的牙刷，所以她借给了我一个。虽然不是很喜欢用别人的牙刷，但在那种情况下也没有其他选择。下次我一定会仔细检查我的行李，确保不会再忘记带牙刷。
Write a brief review of an electric toothbrush you have used or would like to use. Mention its features and benefits, and how it compares to a manual '牙刷'.
Well written! Good try! Check the sample answer below.
Sample answer
我最近开始使用一款新的电动牙刷，感觉比传统的牙刷好很多。它的震动频率很高，清洁效果非常彻底，每次刷完牙都觉得很干净。而且，它还有不同的模式可以选择，比如敏感模式和美白模式，非常实用。虽然电动牙刷比普通牙刷贵一些，但我觉得它的清洁效果和带来的便利是值得的。
小明为什么苦恼？
Read this passage:
小明出差忘记带牙刷，到了酒店才发现。他很苦恼，因为他有口腔敏感问题，对牙刷的选择很讲究。酒店提供的牙刷对他来说太硬了，他担心会损伤牙龈。他考虑去附近的便利店买一把软毛牙刷。
小明为什么苦恼？
文章明确提到“小明出差忘记带牙刷，到了酒店才发现。”
文章明确提到“小明出差忘记带牙刷，到了酒店才发现。”
根据文章，我们应该多久更换一次牙刷？
Read this passage:
牙刷是日常生活中必不可少的清洁工具。为了保持口腔健康，我们应该定期更换牙刷，建议每三个月更换一次。如果牙刷毛变形或磨损，即使不到三个月也应该立即更换。选择适合自己的牙刷，比如软毛牙刷，对保护牙龈也很重要。
根据文章，我们应该多久更换一次牙刷？
文章明确指出“建议每三个月更换一次。”
文章明确指出“建议每三个月更换一次。”
文章中提到的第一把带毛的牙刷起源于哪个国家？
Read this passage:
在古代，人们使用各种天然材料清洁牙齿，比如树枝、骨头或布片。直到15世纪，中国才出现了第一把带毛的牙刷，由猪鬃制成。现代牙刷的演变经历了漫长的过程，从天然材料到尼龙刷毛，再到电动牙刷，每一次创新都极大地提升了口腔清洁的效率和舒适度。
文章中提到的第一把带毛的牙刷起源于哪个国家？
文章提到“直到15世纪，中国才出现了第一把带毛的牙刷”。
文章提到“直到15世纪，中国才出现了第一把带毛的牙刷”。
她总是把她的___放在牙膏旁边。
这句话说的是她把某个东西放在牙膏旁边，根据上下文，“牙刷”是最合理的选择。
为了保持口腔卫生，每天至少刷牙两次，并定期更换___。
刷牙是保持口腔卫生的重要组成部分，而定期更换的是“牙刷”而不是其他选项。
旅行时，我总是随身携带一个便携式的___，以确保牙齿清洁。
为了确保牙齿清洁，旅行时需要携带的是“牙刷”。
儿童用的___通常有更小的刷头和柔软的刷毛。
这句话描述了儿童口腔清洁用品的特点，因此“牙刷”是正确的。
医生建议每三个月更换一次___，以避免细菌滋生。
为了避免细菌滋生，医生建议定期更换的是“牙刷”。
他每天早上都会用电动___刷牙，以达到更好的清洁效果。
为了达到更好的清洁效果，每天早上用的是“牙刷”。
Listen for what he discovered was missing when he brushed his teeth.
Listen for what kind of toothbrush is needed.
Listen for what kind of toothbrush is taken when traveling.
Read this aloud:
你的牙刷多久换一次？
Focus: 牙刷 (yá shuā)
あなたの回答：
Speech recognition is not supported in your browser. Try Chrome or Edge.
Read this aloud:
我需要买一支新的电动牙刷。
Focus: 电动 (diàn dòng)
あなたの回答：
Speech recognition is not supported in your browser. Try Chrome or Edge.
Read this aloud:
请描述一下你理想中的牙刷。
Focus: 理想中 (lǐ xiǎng zhōng)
あなたの回答：
Speech recognition is not supported in your browser. Try Chrome or Edge.
描述一下你理想中的牙刷应该具备哪些功能和特点。
Well written! Good try! Check the sample answer below.
Sample answer
我理想中的牙刷应该具备智能计时功能，提醒我刷牙时间。刷毛要柔软但清洁力强，最好是声波震动的电动牙刷，能更好地清洁牙齿。此外，我希望它能有美观的设计和便携的充电方式。
写一篇短文，探讨一次性牙刷和可重复使用牙刷对环境保护的影响。
Well written! Good try! Check the sample answer below.
Sample answer
一次性牙刷虽然方便，但其大量使用导致的塑料污染问题日益严重。相比之下，可重复使用的牙刷，特别是那些采用竹子或可回收材料制成的，对环境保护更为友好。推广可重复使用的牙刷是实现可持续发展的重要一步，我们应该倡导减少一次性塑料制品的使用，共同为地球的未来努力。
假设你正在为一个新品牌的智能牙刷撰写广告文案，请突出其创新功能。
Well written! Good try! Check the sample answer below.
Sample answer
隆重推出XX智能牙刷，革新您的口腔护理体验！它不仅具备AI智能感应技术，实时分析您的刷牙习惯，更配有UV消毒功能，确保每次使用都洁净如新。通过专属APP，您可以定制个性化刷牙模式，让您的笑容更健康，生活更精彩。
根据文章，以下哪一项关于牙刷历史的说法是正确的？
Read this passage:
牙刷的演变史可以追溯到几千年前。古人曾使用树枝、骨头或动物毛发作为清洁牙齿的工具。现代牙刷的雏形出现于15世纪的中国，而欧洲直到17世纪才开始使用类似的工具。大规模生产和普及则是在20世纪以后。
根据文章，以下哪一项关于牙刷历史的说法是正确的？
文章中提到“现代牙刷的雏形出现于15世纪的中国，而欧洲直到17世纪才开始使用类似的工具”，因此A和D错误。文章也提到“古人曾使用树枝、骨头或动物毛发作为清洁牙齿的工具”，所以C错误。最后一句“大规模生产和普及则是在20世纪以后”支持了B选项。
文章中提到“现代牙刷的雏形出现于15世纪的中国，而欧洲直到17世纪才开始使用类似的工具”，因此A和D错误。文章也提到“古人曾使用树枝、骨头或动物毛发作为清洁牙齿的工具”，所以C错误。最后一句“大规模生产和普及则是在20世纪以后”支持了B选项。
文章指出电动牙刷的缺点是什么？
Read this passage:
电动牙刷因其高效的清洁能力和便捷性越来越受欢迎。与传统手动牙刷相比，电动牙刷通常能去除更多的牙菌斑，并减少牙龈炎的发生。然而，电动牙刷的价格相对较高，且需要定期充电或更换电池。
文章指出电动牙刷的缺点是什么？
文章明确提到“电动牙刷的价格相对较高，且需要定期充电或更换电池”，这与选项C相符。文章也提到“电动牙刷通常能去除更多的牙菌斑，并减少牙龈炎的发生”，所以A和B是错误的。电动牙刷的便捷性是其优点。
文章明确提到“电动牙刷的价格相对较高，且需要定期充电或更换电池”，这与选项C相符。文章也提到“电动牙刷通常能去除更多的牙菌斑，并减少牙龈炎的发生”，所以A和B是错误的。电动牙刷的便捷性是其优点。
根据文章，更换牙刷的频率应该是多久一次？
Read this passage:
选择合适的牙刷对于口腔健康至关重要。一般来说，建议选择刷头小巧、刷毛柔软的牙刷，以便清洁到口腔深处且不伤害牙龈。此外，每三到四个月应更换一次牙刷，或在感冒痊愈后立即更换，以避免细菌滋生。
根据文章，更换牙刷的频率应该是多久一次？
文章中明确指出“每三到四个月应更换一次牙刷，或在感冒痊愈后立即更换”，因此选项C是正确的。
文章中明确指出“每三到四个月应更换一次牙刷，或在感冒痊愈后立即更换”，因此选项C是正确的。
/ 66 correct
Perfect score!
