It is bad manners to talk with your mouth full.

嘴里塞满了东西跟人说话是不礼貌的。

《牛津词典》

A thorough brushing helps to freshen up your mouth.

一番彻底的刷牙处理有助你清洁口腔。

《柯林斯英汉双解大词典》

Look at your mouth.

看看你的嘴巴。

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The outside layers are a bit crunchy, then the soft part takes over and the whole thing seems to just melt in your mouth.

VOA: special.2010.04.12

Today we know, for example, if you can put one certain kind of element in your mouth or eat that, it doesn't necessarily mean you want to put the element next to it and your mouth as well, that might not be safe.

现在我们知道了，比如，即使你能把某一种元素放进嘴里,或者吃下去，这也并不一定意味着,你会把它邻近的元素也吃进嘴里,这可能会有危险，但。

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And everybody can see the food in your mouth.

每个人都能看见你嘴里吃了些什么。

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If you agree with the concept, you can even put your money where your mouth is.

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No one wants to see the frisee hanging out of your mouth like calamari legs.

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But when you hold a pencil further back in your mouth, you are forced to smile.

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