在一电路中，总电阻R与各分电阻R1、R2满足1/R=1/R1+1/R2，则该电路是()。

The phrase 'to sign on'(Para. 2)most probably meansA．to check on the availability of jobs at the jobcentre.B．to accept the government's restrictions on the allowance.C．to register for an allowance from the government.D．to attend a governmental job-training program. 点击查看答案

变压器采用多跟导线并绕的线圈，换位的目的是()。

A.减少导线的涡流损耗
B.降低短路
C.减少电势差引起的导线损耗
D.改善对地电容

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