力的国际单位是公斤力(kgf)。
参考答案:错
The story is moving, and the questions, I suppose, are not so difficult as they appear ______.
A.to answer
B.to be answered
C.answering
D.being answered
发电机调节器工作不良,使调节电压(),容易引起断电器触点烧蚀。
A、过高
B、过低
C、不稳
D、为零