2[简答题] 三相交流异步电动机控制系统中常用的保护环节有哪些？

>> 河南成教 / 电气控制及PLC

河南成教 / 电气控制及PLC

2[简答题]
三相交流异步电动机控制系统中常用的保护环节有哪些？

积分

电气控制及PLC

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[多选题] 在道路上驾驶自行车、电动自行车应当遵守下列规定：（） A.不得牵引、攀扶车辆或者被其他车辆牵引 B.不得双手离把但可以手中持物 C.不得扶身并行、互相追逐或者曲折竞驶 D.不得在道路上骑独轮自行车或者2人以上骑行的自行车道路交通安全管理规划

A.A B.B C.C D.D线性代数

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A.a B.b C.c D.d微积分

题型描述: 阅读理解Laptop computers are popular all over the world. People use them on trains and airplanes, in airports and hotels. These laptops connect people to their workplace. In the United States today, laptops also connect students to their class-rooms. Westlake College in Virginia will start a laptop computer program that allows students to do schoolwork anywhere they want. Within five years, each of the 1,500students at the college will receive a laptop. The laptops are part of a $10million computer program at Westlake, a 110-year-old college. The students with laptops will also have access to the Internet. In addition, they will be able to use e-mail to “speak” with their teachers, their classmates, and their families. However, the most important part of the laptop program is that students will be able to use computers without going to computer labs. They can work with it at home in a fast-food restaurant or under the trees—practically anywhere!Because of the many changes in computer technology, laptop use in higher education such as colleges and universities, is workable. As laptops become more powerful, they become more similar to desktop computers. In addition, the portable computers can connect students to not only the Internet, but also libraries and other resources. State higher-education officials are studying how laptops can help students. State officials also are testing laptop programs at other universities, too. At Westlake College, more than 60 percent of the staff use computers. The lap-tops will allow all users to use computers in their lessons. As one Westlake teacher said, “Here we are in the middle of Virginia and weˊre giving students a window on the world. They can see everything and do everything.”1、 A window on the world in the last paragraph means that students can _ _ _ _ . A. get information from around the world B. attend lectures on information technology C. have free laptops D. travel around the world 2、 The main purpose of the laptop program is to give each student a laptop to _ _ _ _ . A. use for their schoolwork B. work at home C. connect them to libraries D. access the Internet 3、 Why is the word “speak” in the second paragraph in quotation marks？ A. They use the computer language. B. They donˊt really talk. C. None of the above reasons is correct. D. Laptops have speakers. 4、 What can we infer from the passage？ A. am is too expensive. B. The program is successful. C. The program is not workable. D. We donˊt know the result yet. 5、 Which of the following is true about Westlake College？ A. All teachers use computers. B. It is an old college in America. C. 1,500students have laptops. D. Students there can do anything.统考英语A