题目: The car passed through the street ___ are thought was a very dangerous speed.A. which B. at which C. what D. at what 答案: 答案:A
题型:单项选择题 关于牙齿正位器不正确的描述是()。A.用软橡胶或弹性塑料制作B.装置于上下颌所有牙齿的冠部C.有利于咬合关系及牙位的保持,效果良好D.每天晚上戴用,白天也至少戴4小时E.对于排列不整齐或扭转的切牙及深覆的患者保持效果最好 查看答案