A、仅I B、仅I和II C、仅III D、都不能
A、A.’B’ B、B.’\0’ C、C.不确定 D、D.字符’B’的地址
A、S面上的电通量不变; B、S面上的电通量改变,P点的场强不变; C、S面上的电通量改变,P点的场强改变; D、S面上的电通量不变,P点的场强也不变。
A、He’s been taken B、He’ll be taken C、He’s taken
A、He’s taken B、He’ll be taken C、He’ll take D、He’s been taken
A、p>po’>p’ B、p’>p>po’ C、p>p’>po’
A、salvage ship B、container ship C、water ship D、barge
A、Who are you? B、Hello. C、What’s your name? D、Who’s calling,please?