商务卡不提供境外紧急取现服务。（）
参考答案：对
在一闭合电路的某导体中通过的电流与它两端的电压成（）。
A、正比
B、反比
C、无关
D、倍
—I sent him the dictionary by mail this morning.
—You ______ that, for he's coming tomorrow morning.[ ]
A. needn't have done
B. didn't have to do
C. needn't do
D. mustn't do
