单相桥式整流电路中,输出到负载Rfz上的脉动直流电压平均值为()。
A.Ufz=0.45V
B.Ufz=0.5V
C.Ufz=0.9V
参考答案:C
句型转换。
1. She has supper at 7:00 p. m. (对画线部分提问)
______ ______ does she have supper?
2. What time is it now? (同义句转换)
______ the ______ now?
3. Jack has his lunch at school. (改为一般疑问句)
______ Jack ______ his lunch at school?
4. Scott works very long hours every day. (改为否定句)
Scott ______ ______ very long hours every day.
5. I forgot to write a letter to my friend. (改为同义句)
I failed to ______ ______ my friend.
邮购分期在交易完成的情况下提出退款,则需要()个工作日.
A.4
B.5
C.6
D.7