交流电焊机在焊机过程中电流不稳,可能是()
A.电焊机过载
B.焊接件接触不良
C.部分线圈断路
参考答案:B
— Jenny, how was your trip to Beijing?
— Oh, I missed it. I wish I _____ my vacation there. [ ]
A. am spending
B. will spend
C. have spent
D. had spent
薄板厚度在()毫米之间,其宽度通常在0.5~1.5之间的钢板。
A.0.1~3
B.0.2~4
C.0.3~4