问答题 试比较顺铣和逆铣的优缺点。

单项选择题 She ______ study in peace. If she cant, she wont pass her exams. A．has to be able to B．would be able to C．can be able to D．may be able to

单项选择题 造成感觉神经性耳聋最主要的原因是( ) A．耳毒性药物中毒 B．先天性听觉障碍 C．外耳或中耳外伤 D．中耳炎 E．听神经瘤