当有管道穿过剪力墙的连梁时，应预埋套管并保持洞口上下的有效高度不小于下列何值 A．1

I wonder whether there is any girl or boy who does not like to see a rainbow in the sky. It is so beautiful.

There is a story, saying that whenever you see a rainbow you should run at once to the place where it touches the ground, and there you would find a pot of gold. Of course it is not true. You could not find the pot of gold or its end. No matter how far you run, it always seems far away.

A rainbow is not a thing which we can feel with our hands as we can feel a flower. It is only the effect of light shining on raindrops. The raindrops catch the sunlight and break it up into all the wonderful colours which we see. It is called a rainbow perhaps because it is made up of raindrops and looks like a bow（弓).

That is why we can never see a rainbow in a clear sky. We see a rainbow only when there is rain in the air and the sun is shining brightly through the clouds.

Every rainbow has many colours in the same order. The first or the top colour is always red, and the next comes orange, then yellow, and last of all, blue. A rainbow is indeed one of the wonders of nature.

小题1:Children like rainbows because          .

A．they are beautiful

B．they are like bows

C．they can find a pot of gold at the end of a rainbow

D．they are good to crops小题2:We cannot feel          with our hands.

A．a pot of gold

B．a flower

C．a rainbow

D．a raindrop小题3:We can see a rainbow          .

A．when it is raining heavily

B．when it is snowing

C．when it is cloudy

D．when it is becomes fine shortly after raining小题4:Which of the following statements is NOT true?

A．A rainbow is like bow.

B．A rainbow is the effect of light shining on raindrops.

C．Every rainbow has different colours in different orders.

D．A rainbow is one of the wonders of nature.小题5:The first colour of a rainbow is always           .

A．yellow

B．red

C．green

D．blue

肖洛霍夫的长篇小说《静静的顿河》曾获得过诺贝尔文学奖。[ ]

BCR基因表达区别于TCR最大的特点是（）.

A.同种异型排斥

B.共显性

C.同种型排斥

D.具有更多的N-插入

E.高频率体细胞突变

目前制粒中首选的黏合剂是

A．甘露醇

B．淀粉浆

C．蔗糖溶液

D．蜡类

E．交联聚维酮

目前诊断急性心肌梗死最特异的生化指标是（）。

A.CK

B.CK-MB

C.LD

D.cTn

E.Mb