在一个从小要求高度重视清洁和个人卫生社会里，一天刷三次牙是标准的美国习俗。这样可以确保牙齿和牙龈的长期健康。这种传统更为明显地体现为人们每年都去看牙医，以使口腔保持最佳状态。

In a society where cleanliness and personal hygiene are stressed from early childhood，the practice of brushing three times a day is a standard American ritual. This repetitive behavior is designed to ensure the continuing health of the teeth and gums. The traditional character of this rite is evident in the patient's yearly visit to the dentist to maintain the optimum condition of the mouth.

听说美国的牙医收入很高呀