一轿车包括乘客质量1600kg，轿车静止时轮胎与水平地面接触的总面积为0.1m2

镁在二氧化碳中燃烧的化学方程式为2Mg+CO₂C +2MgO。该反应中还原剂是

A．Mg

B．CO₂

C．MgO

D．C

属于表情肌的是（）

A．咬肌

B．颞肌

C．翼内肌

D．翼外肌

E．颊肌

根据国家有关规定，全国固定电话本地网营业区内通话首次3分钟最高资费为：（）

A.0.18元

B.0.20元

C.0.22元

D.0.24元

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.

60().

A.useless 

B.enough 

C.excess 

D.extensive

问题处理系统是联系人与机器及所存储的求解资源的桥梁，主要由（）与（）两部分组成。