卧式砂轮切割机是由工作台面、夹管器、()及电动机组成。
A.皮带
B.防护罩
C.金刚砂切片
D.手柄
参考答案:C
I’m sure you will do better in the test because you ______ so hard this year.
A.studied
B.had studied
C.will study
D.have been studying
欧姆表一般用于测量()。
A、电压;
B、电流;
C、功率;
D、电阻。