根据最小阻力定律,立压一块方钢,当压下量比较大时,文形断面就逐渐变成()。
A、圆形断面
B、方形断面
C、矩形断面
参考答案:A
动词填空(10分)
1. Your brother ___________ (practice) dancing at the moment, isn’t he?
2. My cousin _____________(not swim) so fast as I when we were young.
3. Everyone knows that it’s much easier to say than ___________. (do)
4. The day before yesterday, he made up his mind ______________(lose) weight.
5. The teacher said as much as he could _____________(help)Peter not to drop Chinese.
6. Be quiet! The Greens ______________(plan) their trip to the USA.
7. Look! The new pair of glasses your mother gave you __________(match) your coat very well.
8. Do you have any time ____________(prepare) the dinner for us?
9. Each of us ___________(tell) you the truth when we arrive home.
10. Would you please make all the boys there__________( not talk) in class?
A.用交流电压表测该电源电压时,示数是6V
B.用交流电压表测该电源电压时,示数是6V
C.用此电源给电磁打点计时器供电时,打点的时间间隔为0.01s
D.把标有“6V 3W”的小灯泡接在该电源上时,小灯泡将被烧毁