电源电压不变，R1与R2电阻相等，当开关由断开变为闭合时，电流表的读数
A.变为原来的2倍
B.变为原来的1/2
C.不变
D.无法判断
答案：C
—Well, I forgot to bring my dictionary here yesterday.
—Actually you _____ it here. You were not allowed to use it.
A．needn’t bring
B．needn’t have brought
C．didn’t need to bring
D．don’t have to bring
—Well, I forgot to bring my dictionary here yesterday.