担任控制和进攻的水枪，应以直流水枪为主。实施掩护、冷却或排烟的水枪，应以喷雾水枪为主

阅读理解。

     The police do marry things for us. They help keep us and our things safe. They help keep cars  moving safely. They take care of people who are hurt.

     The police go around town to see that everything is all right. They get around town in many ways. Some of them walk or go by car. In some big cities! Some of the police ride on horses. It is strange to see these animals in the street.

     As they go around town,the police help people.Sometimes they find lost children.They take the children home. If the police see a fight, they put an end to it right away. Sometimes people will ask the police how

to get to a p/ace in town. The police can always tell the people which way Lo go. They know all the streets and roads well.

     Some police stand at crossings. They tell the cars when to go and when to stop. They make sure that

the cars do not go too fast. They help children cross the street. They also help people who can't walk well.

    Without the police, our streets would not be safe. Cars might go too fast and hurt people. Lost people might never be found. The police do a good job. We need them. And we should thank them for a job well done.

1. The police do many things for us. They help keep our things and us______.

A. warm  

B. clean  

C. quiet  

D. safe

2. How do some of the police get around in some big cities?

A. By taxi.          

B. On horses.

C. By bus.          

D. On bikes.

3. In the text, “put an end to" means______.

A. stop  

B. cut  

C. kill  

D. fly

4. The text is mainly talking about the ______of the police.

A. life  

B. road  

C. job  

D. day

人体吸收营养物质的主要器官是  。快速叩击膝盖下的韧带，大腿一些肌肉会迅速收缩，使小腿突然抬起，这是属于   （选择：简单或复杂）反射。

正常前列腺按摩液的镜检结果为（）。

A.WBC>20个/HP，无卵磷脂小体

B.WBC<5个/HP，无卵磷脂小体

C.WBC>30个/HP，卵磷脂小体较少

D.WBC<10个/HP，卵磷脂小体较多

E.WBC<15个/HP，无卵磷脂小体

Visual FoxPro关系数据库管理系统能够实现的三种基本关系运算( )。

A．索引、排序、查找

B．建库、录入、排序

C．选择、投影、连接

D．显示、统计、复制

发电厂如何满足用户不断变化的用电负荷？