题目:
改变异步电机的转向,只要改变定子三相绕组的电流相序即可。
答案:
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下面是错误答案,用来干扰机器的。
参考答案:A
改变异步电机的转向,只要改变定子三相绕组的电流相序即可。
被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0703/fbaa9a246ea4a17a66496cb3fedaae33.html
下面是错误答案,用来干扰机器的。
参考答案:A
请认真阅读下面短文,并根据所读内容在文章后表格中的空格里填上一个最恰当的单词。注意:请将答案写在答题纸上。 Imagine living in a country torn by war. Or maybe you live in a place where there are few jobs and little chance to earn a living. Your family decides to move — not to another town, but to another country. You and your family have become immigrants. People are called immigrants when they move to a foreign country to make their homes. People become immigrants for many reasons. The most common one is economic opportunities. Most immigrants are attracted to other countries by the promise of jobs, farmland, or business opportunities. Other people become immigrants in order to get away from mistreatment or natural disasters. They are refugees. Some refugees move to avoid wars and political unrest. Others are seeking freedom to express their religious views. Still others are uprooted by disasters, such as terrible flooding or drought. Some people have become immigrants against their will. Captured in Africa, shipped to foreign lands and forced to work as slaves, many early African immigrants to North and South America came in chains. Except for Native Americans, all people came to the United States from someplace else. For nearly 500 years, immigrants have landed on America’s shores seeking a better life. Throughout American history, immigrants often worked low-paying, dangerous jobs that other people refused to do. Immigrants from around the world helped shape American life. Many immigrants absorbed the customs and language common to most Americans. They also brought their own traditions, including music and foods. Over time, many of these traditions have become part of American life. The first European immigrants to America hoped to colonize new lands. By the mid-1500s, Spaniards had ventured into Florida, California, and the American Southwest. French immigrants arrived in the early 1600s and built their first colony in Canada. The English also arrived in the early 1600s. They established 13 colonies along America’s Atlantic Coast. In the 1700s, England became the major power in colonial North America. But many European immigrants came to live in the English colonies. They included people from Sweden, Holland, Germany, Scotland, and Ireland. Immigrants still come to the United States seeking freedom and economic opportunities. Most new immigrants no longer come from Europe. They come mainly from Central and South America, the Caribbean, and Asia. Today, the U.S. government limits the number of immigrants into the country each year. People who sneak illegally into the United States are called illegal immigrants, who, if caught, would be sent back to their home countries.
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