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问题 填空题

一根蜡烛长20cm，点燃后每小时耗去5cm，设燃烧后剩下的长度为Scm，则S与t之间的函数关系式是S=（    ），自变量t的取值范围是（    ）。

答案

S=20-5t，0≤t≤4

选择题
某人看路边的树木向东运动，若以地面为参照物，则该人的运动情况是（　　）

A．向东运动

B．向西运动

C．向南运动

D．向北运动
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单项选择题

The process of gaining or losing weight can be explained by comparing your body to your car. Both run (51) fuel, food for your body and gasoline for your car. Both (52) that fuel, first into heat, then energy, some of (53) is used to do work, and some emitted as waste. And (54) your car uses more energy when the engine is racing than when it is idling, (55) does your body use more energy when you are working hard than (56) you are resting.

For the purpose of this comparison, (57) , there is one significant difference between them. Your car cannot store fuel by turning it into (58) else; all gasoline not (59) remains as gasoline. But your body stores (60) energy as fat. When the gas tank is completely empty, the car won’t run; but your body can burn fat to provide more energy.

57().

A.however 

B.therefore 

C.moreover 

D.likewise
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