出现（）情况时，应将变压器瓦斯保护停用。A.变压器退出运行 B.预报有地震可能 C.

具体劳动和抽象劳动的关系是( )。

A．抽象劳动寓于具体劳动之中

B．两者是对立统一的关系

C．两者是同一劳动过程不可分割的两个方面

D．具体劳动反映人与自然的关系，抽象劳动反映社会生产关系

鱼类调查指标包括（）。

A.种类组成与分布

B.渔获密度、组成与分布

C.渔获生物量、组成与分布

D.经济鱼类和常见鱼类

将考生文件夹下DONG\OUM文件夹中的文件SSE.HLP移动到考生文件夹下JING文件夹中，并将该文件改名为PIDU.DOC。

A

Hello,everyone. Because of the high rate of school violence(力)in some areas, teenagers’ safety becomes a serious problem. We are planning to set up an organization named School Watch to make sure that students have a safe school environment. Please be part of our plan!
What is School Watch
School Watch is a volunteer project in our school. It helps us stop violence and improve the quality of school life. It will keep yourself and your schoolmates safe. The other members of School Watch care for you and your classroom and you do the same for them.
Is it for everyone
Anybody can become a member of School Watch because everyone has something to offer.
What else can it do
School Watch makes it possible for us not only to help each other But also to make friends with each other. Some members may offer to help schoolmates who have problems with their homework.
Who is the Best School Watcher
Our school will look for the Best School Watcher and give him or her lots of prizes. You could be the one !
How do you start
To be part of this plan, the only thing you need to do is to talk to the director of the plan in your grade. If you want to get more information, check the official website at www.schoolwatch.com.

Anyone can become a member of School Watch because ______.

A．everyone may have problems

B．everyone is useful

C．everyone needs to make some friends

D．everyone can give help to others

管道施工时，用推土机械或碾压机械碾压，管顶以上的覆土厚度不应小于（）cm。

A、50

B、60

C、70

D、80