桥式起重机上由于采用了各种电气制动,因此可以不采用电磁抱闸进行机械制动。()
参考答案:错
A boy with two dogs _____ when the earthquake rocked the city. [ ]
A. were sleeping
B. is asleep
C. was sleeping
D. are asleep
短暂性脑缺血发作(TIA)后神经功能完全恢复的时间最长不超过()。
A.1小时
B.6小时
C.12小时
D.24小时
E.36小时