为防止钢丝绳锈蚀损伤，要（），对于经常处于运动状态的钢丝绳涂油是必不可少的。
A、勤检查
B、勤调整
C、勤去污
D、勤涂油
参考答案：D
---What did your mother say on the phone just now?
--- She asked me _____ I was getting on well with my new classmates.
A．that
B．if
C．how
D．what
最早的外科医师称为（）
A.疾医
B.疡医
C.食医
D.兽医
E.大方脉
