气化升压器在正常运行过程中，若气化器液相入口管很凉，气相出口管很热，即说明运行正常。

阅读理解。

    Mr. Black was a policeman. He was a kind person. He liked to have a walk in the park after breakfast.

    It was very cold on a winter morning. Mr. Black was walking along the street when he heard a cry for

help. He turned around but could see nobody. He stopped and looked here and there. At the moment, a

boy ran up to him. The boy was in such a hurry and he couldn't say a word except pointing towards the

river. Mr. Black ran to the river as soon as possible. Both of them ran along the river and saw a girl in the water. She was holding a piece of wood. It was carrying her away. It was too dangerous.

    Without a word, Mr. Black took off his clothes as quickly as he could, and jumped into the river. He

swam to the girl and took her back near the bank and lifted the girl up, and then the boy helped pull her

out of the water. Then they stopped a car and took the girl to the hospital. At last the girl's life was saved, and she thanked them very much.

1. What do you think of Mr. Black?

A.Mr. Black is a kind man.  

B.Mr. Black is a good policeman.

C.Mr. Black liked to have a walk.

2. When did Mr. Black find the girl?

A.As soon as he heard the cry for help.

B.When the boy ran to him.

C.When they ran along the river.

3. Why didn’t the boy say a word?

A.He was too worried.

B.He was too excited

C.He was too sad

4. How was Mr. Black when he came back to the bank.

A.His clothes were all wet.

B.He felt very cold.

C.He was angry.

5. According to the passage, which is right?

A.The girl thanked Mr. Black and the boy.

B.The boy was the girl’s brother.

C.Only the boy sent the girl to the hospital.

下面对密封油高位油槽理解正确的是（）。

A、机组停车时提供密封油

B、保持稳定的油气压差

C、密封油系统有故障时提供密封油

D、压缩机内无压力时，密封油高位槽无油

已知等腰梯形的锐角等于60°，它的两底长分别为15cm和49cm，则它的一腰长为（　　）

A．49cm

B．15cm

C．32cm

D．34cm

如图所示，在y轴上A点沿平行x轴正方向以v₀发射一个带正电的粒子，在该方向上距A点3R处的B点为圆心存在一个半径为R的圆形有界的匀强磁场，磁场方向垂直纸面向外，当粒子通过磁场后打到x轴上的C点，且速度方向与x轴正向成60°角斜向下，已知带电粒子的电量为q，质量为m，粒子的重力忽略不计，O点到A点的距离为2

（1）该磁场的磁感应强度B的大小

（2）若撤掉磁场，在该平面内加上一个与y轴平行的有界匀强电场，粒子仍按原方向入射，当粒子进入电场后一直在电场力的作用下打到x轴上的C点且速度方向仍与x轴正向成60°角斜向下，则该电场的左边界与y轴的距离为多少？

（3）若撤掉电场，在该平面内加上一个与（1）问磁感应强度大小相同的矩形有界匀强磁场，磁场方向垂直纸面向里，粒子仍按原方向入射，通过该磁场后打到x轴上的C点且速度方向仍与x轴正向成60°角斜向下，则所加矩形磁场的最小面积为多少？

现在有些快递企业使用（）来监视快件车辆的运输路线。

A、EDI

B、GPS

C、GIS

D、RFID