问题 填空题

物理学中我们把______的方向规定为电流方向,金属导体中的电流方向与自由电子移动方向______.在电路中,电流的方向是从电源______极经用电器流向______极.

答案

由电流方向的规定可知,正电荷定向移动的方向为电流方向;金属导体中的电流方向与自由电子移动方向相反;

电路接通时,电源外部电流总是从电源的正极出发,经过用电器,回到电源的负极的.

故答案为:正电荷定向移动;相反;正;负.

完形填空

This is a true story . One evening a woman was   36    home when she saw a truck close behind her . She drove more quickly to be far away from the truck ,   37    when she sped up (加速),the truck did ,too. The   38   she drove , the faster the truck drove . The woman felt afraid , so she drove onto a main street , hoping to   39  the truck in a traffic . But the truck jumped a   40  light and went on running after her .

Finally the woman drove her car into a service station ,and got out of her car ,shouting for   41  .  The truck driver didn' d leave , instead he went out of his car .  He   42   the back door , and pulled out a man hidden (藏)in the back seat . The woman was running from the wrong person .the woman was   43  at last .

From the place where the woman stopped her car , the driver   44 a criminal (罪犯)in the woman' s car . The driver drove after her not to   45   her but to help her .

小题1:A. running         B. walking       C. driving.

小题2:A. but             B. though        C.  or.

小题3:A. bigger          B. faster         C. happier.

小题4:A. lose            B. look          C. come

小题5:A. black           B. red           C. green.

小题6:A. advice          B. suggestion    C. help

小题7:A. cleaned         B. opened       C. bought.

小题8:A. safe            B. healthy        C. free

小题9:A. forgot          B. found          C. put.

小题10:A. harm          B. visit.        C. save.

判断题