They went on working _______ it was very late. [ ]
A. than
B. if
C. though
D. because
答案:C
存储环节(窝点)案件突发情况的处置方法?
汽车维修厂三相四线制交流供电系统中,各相电动势()
A.瞬时值相同
B.最大幅值不同
C.相位相同
D.同一时刻的幅值不一