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模块机器人--自动循迹光电小车能沿着黑色胶带前进，利用两对发光管和光敏管，并用单片机控制左右轮子的转速．其中光敏管充当______器，单片机充当______器，电动机和轮子充当______器．

答案

利用两对发光管和光敏管，确保车沿着黑色胶带前进，运用光的传感器原理；

单片机控制左右轮子的转速，是确保向什么方向行驶；

电动机和轮子是车能前进的动力，是赶到执行的作用．

故答案为：传感；控制；执行．

选择题

如果鱼的大小、鱼缸的大小均相同，均密封后放置在阳光下，下述实验装置中哪一个鱼缸中的鱼可能先死

A．一缸清水，1条鱼

B．一缸清水，5条鱼

C．一缸清水，10条鱼加一部分水藻

D．一缸清水，10条鱼
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完形填空

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1). Some festivals are held to honour the dead or to ___1_____ the ancestors, who might return _____2__ to help or to do ____3____. For the Japanese festival Obon, people should go to clean graves and light incense in ____4____ of their ancestors. They also light lamps and play music because they think this will __5_____ the ancestors back to earth. In Mexico, people celebrate the Day of the Dead in early November. _6____ this important feast day, people eat food in the _7____ of skulls and cakes with “ bones” on them. They offer food, flowers and gifts to the dead. The Western holiday Halloween also had its ___8______in old _____9_ about the return of the spirits of dead people. It is now a children’s festival, when they can dress up and go to their neighbours’ homes to ask for sweets. If neighbours do not give any sweets, the children might play a __10____ on them.

2)       According to a widely ____1___ theory, the universe began _____2__ a “Big Bang” that threw matter in all _____3____. After the “Big Bang”, the earth was still just a cloud of dust. ___4____ it was to become was uncertain until between 4.5 and 3.8 billion years ago when the dust _____5___ into a solid _____6__. The earth became so _____7___ that it was not clear ____8_____ the shape would last or not. It ____9______ loudly with fire and rock. They were in time to produce carbon, nitrogen, water vapour and other gases, which were to make the earth’s ___10______.
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