选词填空。complete, pronounce, produce, impre_爱下问搜题

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问题填空题

选词填空。

complete, pronounce, produce, impress,
lose, divide, use, terrify, design, waste

1. The little girl _____ _____ by the dog.
2. Most foreigners _____ _____ by the hospitality of the Chinese people.
3. In the past few years, many new styles of dress _____ _____ _____ by this lady.
4. The word _____ _____wrong.
5. Many cars _____ _____ _____ by the factory next month.
6. Time shouldn't _____ _____ , boys and girls.
7. The railway _____ not _____ _____ yet.
8. The whole class _____ _____ into eight groups.
9. Pens _____ _____ to write with.
10. Anna's new bag _____ _____ yesterday.

答案

1. was terrified

2. were / are impressed

3. have been designed

4. was pronounced

5. will be produced 6. be wasted

7. has, been completed

8. was divided

9. are used

10. was lost

问答题

两相互平行且足够长的水平金属导轨MN、PQ放在竖直平面内，相距0.4m，左端接有平行板电容器，板间距离为0.2m，右端接滑动变阻器R．水平匀强磁场磁感应强度为10T，垂直于导轨所在平面，整个装置均处于上述匀强磁场中，导体棒CD与金属导轨垂直且接触良好，棒的电阻为1Ω，其他电阻及摩擦不计．现在用与金属导轨平行，大小为2N的恒力F使棒从静止开始运动．已知R的最大阻值为2Ω，g=10m/s²．则：

（1）滑动变阻器阻值取不同值时，导体棒处于稳定状态时拉力的功率不一样，求导体棒处于稳定状态时拉力的最大功率．

（2）当滑动触头在滑动变阻器中点且导体棒处于稳定状态时，一个带电小球从平行板电容器左侧，以某一速度沿两板的正中间且平行于两极板射入后，在两极板间恰好做匀速直线运动；当滑动触头位于最下端且导体棒处于稳定状态时，该带电小球以同样的方式和速度射入，小球在两极板间恰好做匀速圆周运动，则小球的速度为多大，做圆周运动的轨道半径多大？

填空题

变压器除了能改变交变电压外，还可以改变（）、变换阻抗以及改变相位等。