【单选题】Soon they ____________ the water which ____________ the pipe.
B.
ran out of; ran out of
【单选题】At last her money for singing lessons _________. [ ]
【单选题】全波整流电路整流电压的脉动系数为( )。
【单选题】慢性焦虑症即广泛性焦虑。其症状较多,但不包括( )
【简答题】The speaker ________ his notes before the lecture. A) ran down B) ran into C) ran out D) ran over
【简答题】A.ran after B.ran into C.ran over D.ran to
【单选题】The printer ______paper.
【简答题】三相半波可控整流电路,输出到负载的平均电压波形脉动频率为 HZ;而三相全控桥整流电路,输出到负载的平均电压波形脉动频率为 HZ;这说明 电路的纹波系数比 电路要小。