总风无压力空气的情况下,要缓解机车弹停装置,必须( )。
A. 按压司机室弹停装置缓解按钮
B. 按压气阀柜弹停模块上的缓解脉冲电磁阀
C. 手拉4个弹停风缸的缓解拉杆
he following are the factors that have contributed to the development ofthe U.S. economy except ______.
A. the vast space and resources of the land
B. the ideals of freedom and economic opportunity
C. English as its national language
D. hard work by the people
Which of the following is not true of the U.S. economy?
A. It is based largely on a free enterprise system.
B. There is little government involvement in the economy
C. It is one of the least regulated economies in the world.
D. Many of the nation's basic industries are represented by only a few major corporations.
Which of the following is not true of U.S. agriculture?
A. It is the most efficient in the world.
B. About a third of the world's food exports come from U.farms.
C. The use of modern farm machinery and agricultural methods has helpedmake U.farms the most efficient in the world.
D. The number of farms in the United States has increased since 1925.
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