线路纵断面由平道、坡道以及设臵在坡道变化处的（）构成。_爱下问搜题

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问题填空题

线路纵断面由平道、坡道以及设臵在坡道变化处的（）构成。

答案

参考答案：竖曲线

完形填空

Life in the 22^nd century will be different from that in the 21^st century because many changes will happen in the new century. 1_____ what will the changes be?
First, the population is growing very fast. There 2      more and more people in the world and most of them will live longer than before. Computers will be 3     smaller and more useful, and there will be 4     one in every home. And 5      studies will be one of the most important subjects in schools.
Second, people will work 6      hours than they are doing in the 21^st century. They’ll have more free time for sports, watching TV and7    . Traveling will also be cheaper and easier. And more people will go to8      countries for holidays.
Third, there will be changes in our food, too. People will use more land to 9      new towns and houses. Then there will be less room for cows and sheep, so 10       will be more expensive. Maybe no one eat it everyday; 11     , they will eat more vegetables and fruit. Maybe people will be 12     .
Last, work in the future will be13      , too. Robots will do the 14     and hard work. Because of this, many people won’t have 15     work to do. This will be a problem.

C．no more than

判断题

荧光灯主要是利用放电产生紫外线辐射激发荧光粉层而发光。