第13题: [单项选择]What will they do A. They will go swimming. B. They will go for a walk. C. They will go to the cinema. 参考答案:A 答案解析:[听力原文] W: Would you like to go swimming with me this afternoon M: Yes. That’s a good idea.
第18题: [单项选择]牙龈受到食物的直接撞击而受伤,引起牙龈萎缩是由于 A. 牙冠轴面凸度正常 B. 牙冠轴面凸度过小 C. 牙冠轴面凸度过大 D. 牙冠轴面呈凸面 E. 牙冠轴面呈凹面 参考答案:B 答案解析:牙冠的正常突度可使部分咀嚼过的食物擦过牙龈的表面,起按摩作用,促进血液循环,有利于牙龈的健康;若牙冠突度过小或平直,食物可直接撞击牙龈,使牙龈产生创伤性牙龈萎缩;若牙冠突度过大,食物经过该处则不能触及