As soon as she entered the room, the gir
题型：选择题
问题：
As soon as she entered the room, the girl caught sight of the flowers ________ by her mother.
A．buying
B．being bought
C．were bought
D．bought
题型：选择题
| 如图所示为一磁流体发电机示意图，A、B是平行正对的金属板，等离子体（电离的气体，由自由电子和阳离子构成，整体呈电中性）从左侧进入，在t时间内有n个自由电子落在B板上，则关于R中的电流大小及方向判断正确的是（ ） A．I= B．I= C．I= D．I=  |
