能介导白细胞间相互作用的细胞因子称为（） A.CSF B.IL C.TNF D.单核

（1）如图所示，一横波的波源在坐标原点，x轴为波的传播方向，y轴为振动方向．当波源开始振动0.5s时形成了如图所示的波形（波刚传到图中P点）．则：该波的振幅为______；波从图示位置传到Q点所用时间为______；Q点开始振动的方向为______

（2）在水面上放置一个足够大的遮光板，板上有一个半径为r的圆孔，圆心的正上方h处放一个点光源S，在水面下深H处的底部形成半径为R的圆形光亮区域（图中未画出）．测得r=8cm，h=6cm，H=24cm，R=26cm，求水的折射率．

Once upon a time in a land far away, there was a wonderful old man who loved everything：animals, spiders, insects．．．

One day while walking through the woods, the nice old man found a cocoon（茧）of a butterfly．He took it home．A few days later, a small opening appeared; he sat and watched the butterfly for several hours as it struggled to force its body through that little hole．Then it seemed to stop making any progress．It appeared as if it had gotten as far as it could and it could go no farther．Then the man decided to help the butterfly, so he took a pair of scissors and cut off the remaining bit of the cocoon．

The butterfly then appeared easily．

But it had a swollen body and small, fragile wings．The man continued to watch the butterfly because he expected that, at any moment, the wings would enlarge and expand to be able to support the body, which would be smaller in time．Neither happened! In fact, the butterfly spent the rest of its life crawling （慢慢爬行）around with a swollen body and fragile wings．

It never was able to fly．

What the man in his kindness and hurry did not understand was that the limited cocoon and the struggle required for the butterfly to get through the tiny opening were Nature’s way of forcing fluid （液体）from the body of the butterfly into its wings so that it would be ready for flight once it achieved its freedom from the cocoon．

Sometimes struggles are exactly what we need in our life．If we were allowed to go through our life without any obstacles and difficulties, it would disable us．We would not be as strong as what we could have been．And we could never fly．

小题1:The butterfly could never fly because ________．

A．it was too fat and strong．

B．it loved crawling around．

C．it got out of the cocoon easily．

D．it didn’t get through the cocoon ．小题2:The text is most likely to be found in a book about__________．

A．popular science

B．humorous stories．

C．successful people

D．philosophy events ．小题3:What is the implied meaning of the passage?

A．Life without any obstacles and difficulties is perfect．

B．Obstacles and difficulties contribute to success．

C．Never help a butterfly to get out of the cocoon．

D．A butterfly can never fly without going through the cocoon．

本公司计量器具标记，合格标签与免校标签为（），禁用或封存标签为（）；钢卷尺采用（）的方式进行标识。

地形图上0.2mm所代表的实际水平距离叫做地形图比例尺精度。

炉管表面金相检查的目的是什么？一般采用哪些方法？检查中应注意哪些问题？