问题
选择题
某交流电电源电压的瞬时值表达式为u=6 sinl00πt（V），则下列说法中正确的是（ ）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6 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 |
V
答案
答案：A
搜题请搜索小程序“爱下问搜题”
| 某交流电电源电压的瞬时值表达式为u=6sinl00πt（V），则下列说法中正确的是（ ） 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6 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 |
答案：A
A man lost his legs in a tragic accident. After the accident, only two fingers 36 on his right hand. However, he was bright, creative and educated. He had gained much experience while traveling throughout the world. Yet, he became very 37 after the accident. He was afraid he would spend his life 38 and would no longer be able to live a life in a(n) 39 way. One day, he remembered how he had 40 loved getting letters. He realized that he still had partial 41 of his right hand and could write with difficulty. Then, he had an idea. “Why not write to other people who need 42 ?” Who to write to? He thought of people in prison. Many of them hoped to 43 their freedom. Others would keep feeling sad and remain locked away for the rest of their lives. He decided that he must try to 44 them. He wrote to a prison officer about sending letters to prisoners. The prison officer replied that writing to the prisoners would be 45 . However, it would be 46 prison rules for them to write back. Filled with the 47 of carrying out his idea, the man knew he had to write. He began sending one-way 48 of love, hope, strength and encouragement. He 49 twice a week, testing his strength and ability to the limit. He poured his heart and soul into his words, 50 his experience and optimism. It was difficult to write those letters, especially without hope of a 51 . Frequently, he felt discouraged. He often wondered if anyone 52 read his letters. However, he determined to 53 as long as he could help others. One day he received a letter from the prison officer. It was a short note from the officer who monitored and 54 the prison mails. The letter said, “Please write on the best paper you can 55 . Your letters are passed from cell (牢房) to cell until they fall to pieces!”
|