题目

如图所示，理想变压器的原副线圈的匝数比n1：n2=2：1，原线圈接正弦式交流电，副线圈接电动机电动机线圈电阻为R，当输入端接通电源后，电流表读数为I，电动机带动一质量为m的重物以速度v匀速上升，若电动机因摩擦造成的能量损失不计，则图中电压表的读数为（  ） A．4IR+   B． C．4IR    D． IR+阅读短文，下列问题A girl who graduated from a world famous university wanted to do translation work for authority leaders. She was so happy when she entered the British Embassy (大使馆). She thought it was the greatest happiness in her life as many graduates wanted to get that job and she was one of the few people who got it!But when she started her new job, she realized that it was just a job of answering calls and recording staff members'arriving and leaving times. It was supposed to have no future. For some time, she felt disappointed and didn't know what to do. However, she didn't want to give up this job. She thought about it for one or two days and finally she decided that she would try her best to do this job. From then on, she learnt to appreciate her own job. She wrote down the names and phone numbers of the staff members on a notebook so that she could remember them. She found great pleasure in dealing with the daily chores. When a phone call came in, she picked up the phone as soon as possible. When someone asked her about who was not in the office, she would give the right name and even the time when he or she left. Nobody could do that except her.Her excellent work received praise not only from the embassy's members, but also from people in the local government. A leader of a famous company in Britain was deeply impressed by her, so he invited her to work for him. After that she became the leader's personal translator and she was appreciated by the foreigners.We cannot choose our destiny(命运), but we can choose the attitude with which we face our life. Maybe the attitude could change our destiny.（1）What was once the girl's greatest happiness in her life?A.Becoming a leader's translator.B.Graduating from the university.C.Working in the British Embassy.D.Continuing her study in the university.（2）What can we learn from the second paragraph?A.The girl was happy to make lots of money.B.The girl once lost heart for some time.C.People thought the girl was very lucky.D.The girl did a very important job in the British Embassy.（3）Why was the girl invited to work for the company?A.Because of her rich experience.B.Because of her rich knowledge.C.Because of her attitude towards workD.Because of her excellent English.（4）What does the author want to tell us?A.Everybody has his or her own hard time in life.B.We should take a positive attitude towards life.C.We should be ready to give a hand to our friends.D.It is important to listen to others' problems carefully.（5）What's the best title for this passage?A.A clever girl.B.Attitude is a key to everythingC.A good choice.D.It's just good luck.