在示波器的使用实验中,在测量外界待测信号时,通常示波器的X轴使用()
A.机内扫描信号
B.机内正弦波信号
C.机外扫描信号
D.机外正弦波信号
参考答案:A
— The window must have taken you quite a lot of time that day.
— You are right. They _____ for weeks.
[ ]
A. haven't been cleaned
B. hadn't been cleaned
C. didn't' clean
D. haven't cleaned
根据《职业病防治法》,职业病伤残等级的鉴定办法由()制定。
A.国务院劳动保障部门
B.国务院劳动保障行政部门会同国务院卫生行政部门
C.国务院卫生行政部门
D.国务院劳动行政部门A.国务院劳动保障部门