Chewing gum, once bought primarily by adolescent boys, is now featured in commercials as a breath freshener and teeth cleanser for use after a meal.

曾经主要由青少年购买的口香糖，现在在广告中被用作饭后的口气清新剂和牙齿清洁剂。

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Scientists say the diet of prehistoric humans probably required more chewing teeth.

科学家们表示，史前人类的饮食可能需要更多咀嚼齿。

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Sealants are protective coatings placed over the tops of chewing teeth - molars and premolars.

封闭剂在是牙齿咀嚼面上覆盖一层保护材料——在磨牙或者前磨牙。

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They swallowed it whole. Their teeth were used to rip the meat or plants into mouth-sized pieces, but were not used for chewing.

VOA: special.2010.06.04

Scientists say the diet of prehistoric humans probably required more chewing teeth.

VOA: special.2011.08.10

The changes were made because it was discovered that infective endocarditis is more likely to occur after frequent exposure to bacteria from routine activities such as chewing food or brushing one's teeth than from occasional dental, gastrointestinal tract or genitourinary tract procedures.

CNN: Why do I no longer need an antibiotic before teeth cleaning?

The saliva produced in the mouth by the physical act of chewing can wash away acids and bacteria, thereby protecting teeth.

CNN: Chew on this: Gum may be good for body, mind