随机误差是测定值受各种因素的随机变动而引起的误差，它出现的概率通常遵循正态分布规律

组装式消防水泵结合器正确的安装顺序应是接口、本体、()。

A.联接管、控制阀、安全阀、放空管、止回阀

B.放空管、控制阀、安全阀、联接管、止回阀

C.止回阀、联接管、控制阀、安全阀、放空管

D.联接管、止回阀、安全阀、放空管、控制阀

We all have our own ways of sharing our life experiences with others.

Photographers use cameras, artists use brushes, musicians use songs and writers use stories.

Spencer Johnson’s story Who Moved My Cheese? shows changes exist in(存在于)our life. Life changes and so we do. We must change ourselves to face the changing environment, or we will fail.

Just look at the cycle(循环)of the seasons. Trees bud(发芽)in spring and in summer their leaves turn green. In autumn, their leaves start to fall onto the ground. When winter comes, there are no leaves on trees. Next spring the cycle begins again. Since we know there are cycles in nature, we can prepare for them. We know it is colder in winter and hotter in summer, so we can dress properly.

Since we accept the cycles of nature, we should also accept the changes in our life.

We can prepare ourselves for changes by becoming more flexible(灵活的). We can regard the changes in our life as chances. As we keep changing ourselves, we can keep up with the changes in our life.

小题1: What do writers use to share their life experiences?       

A．Stories.

B．Newspapers.

C．Basketballs.

D．Pianos.小题2:Who Moved My Cheese? tells us that ______________.

A．changes exist in our life

B．we should move others’ things

C．we should use books to share our life experiences

D．there are difficulties in our life小题3: The cycle of the seasons means _____________.

A．we should wear warm clothes in winter

B．we should accept the changes in our life

C．we should prepare for the weather

D．leaves turn yellow in autumn小题4:If you fail a test, what should you think according to the passage?

A．I have no chance to pass the test.

B．Exams are hard for me.

C．I have bad luck.

D．It’s good for me because I know there are more to learn.小题5:What’s the main idea of this passage?

A．Weather changes in different seasons.

B．Who Moved My Cheese? is a good book.

C．We should change ourselves when life changes.

D．We should not lose heart when we meet with difficulties.

{a_n}为等差数列，公差为d，S_n为其前n项和，S₆＞S₇＞S₅，则下列结论中不正确的是（　　）

A．d＜0

B．S₁₁＞0

C．S₁₂＜0

D．S₁₃＜0

基金销售机构可以选择（）或者支付机构从事基金销售支付结算业务。

A.商业银行

B.证券公司

C.保险公司

D.基金公司

《中国药典》2010版规定口服液体制剂每毫升细菌数不得超过（）

A.1000个

B.500个

C.100个

D.50个

E.10个