问题
单项选择题
电源调试通电前应检查印制电路板上接插件是否正确到位、(),以发现存在的问题,有利于提高工作效率。
A、铜膜是否太宽
B、焊盘位置是否设计正确
C、焊点是否有虚焊和短路
D、铜膜是否太窄
答案
参考答案:C
电源调试通电前应检查印制电路板上接插件是否正确到位、(),以发现存在的问题,有利于提高工作效率。
A、铜膜是否太宽
B、焊盘位置是否设计正确
C、焊点是否有虚焊和短路
D、铜膜是否太窄
参考答案:C
阅读理解。 | |
Forests are large pieces of land covered with big trees. They are found all over the world, especially in places where there is enough sunshine and much rainfall. 1______ To build a house, we need wood for doors and windows. Beautiful chairs and tables are also made of wood. Teak (柚木) wood is very useful for ship-building. It is used for all parts of a ship where wood and metal come in contact (接触), for it has a kind of oil to keep metal away from rust (铁锈). 2______ For this, teak wood is an important railway building material. Forests are no less important than useful. They are the home of wild animals. Without them, those animals would run among the places where we live and work. 3______ Forests are helpful to weather, too. When it is very hot, they can be a good place for people to stay away from the sun. In winter, they can keep us from the cold. Forests can also stop the land from being washed away by heavy rain for the trees hold the soil together. 4______
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5. What's the best title for the passage? | |
A. Forests and Animals B. Forests are all Over the World C. Forests are Important D. We never Cut Down the Trees |