各单位库存限额原则上每年核定（）次。 A.1 B.2 C.3 D.4

口腔颌面部外伤出血最有效的止血方法是()

A．填塞止血

B．结扎止血

C．指压止血

D．包扎止血

E．药物止血

根据短文内容，判断正(T)误(F)。

     These two letters appeared in a newspaper. Both writers have their own ideas on zoos.

     Zoos Do a Good Job

     It is good to keep animals in zoos. I know a lot of people think it is wrong to keep animals in zoos.

However, I believe that zoos have many good points.

     Firstly, zoos are places for people to see many different kinds of animals from all over the world. Without

zoos, most people would never see a real bear or tiger.

     Secondly, zoos look after the animals very well. The animals are always given food and cleaned regularly.

In the wild, it is not always possible for an animal to find food, so sometimes it goes hungry. But animals kept

in zoos never go hungry.

     Thirdly,zoos protect the animals. They offer them safety in danger of becoming extinct (灭绝). But zoos

give these animals a chance to live. Without zoos, there would be fewer kinds of animals in the world.

                                                                                                                                      Maria Smith

      Zoos Are Unnatural 

      In Maria's letter, she says that zoos are good for animals. I am afraid that zoos are not good for animals,

and they are only good for people.

      It is unnatural (非自然的)and unfair to keep wild animals in cages. Most animals are kept in cages. They

are too small for them. In the wild, these animals would travel freely. In zoos, they can't do this. This is why

the bears and tigers always look so sad.

     Most cages are not very clean either. It is true that zoos give the animals food regularly. But this is not

natural. Wild animals are used to looking for their own food. We should treat animals in the same way that

we treat other people with respect.

     Would anyone be happy if you don't let him go out of his home? Would Maria like to have lots of people

standing outside her flat looking at her? No, she wouldn't. And animals don't like it either.

                                                                                                                                 Philip White

( )1. Maria and Philip have quite different ideas on keeping animals in zoos.                 

( )2. In Maria's opinion, a real bear or tiger can only be seen in zoos.                      

( )3. Maria thinks that animals live better in zoos than in the wild.                         

( )4. According to Philip, if cages are big and clean enough, tigers and bears will look happy.

( )5. Maria and Philip both agree that zoos are good for people.                              

( )6. In the two letters, they are discussing how to make animals in zoos happy.              

2003年12月23日川东北气矿16号矿井发生“井喷”事故，造成两百多人死亡．据悉，发生事故的16号矿井所在气田共有五六百亿立方米的天然气储量，是西南地区的大气田，同时也是高含硫气田（含有硫化氢气体）．此次事故死亡和受伤者主要都是硫化氢（H₂S）气体中毒．硫化氢为无色气体．具有臭蛋味，易溶于水．硫化氢经粘膜吸收快，皮肤吸收甚慢．人吸入硫化氢会出现呼吸道及眼刺激症状；会发生肺水肿、支气管炎及肺炎，出现头晕、头痛、步态不稳、恶心、呕吐症状；吸入1000毫克/立方米数秒钟后出现急性中毒，导致呼吸加快后呼吸麻痹而立刻死亡．

（1）天然气的主要成分是______；

（2）去年，我国发生了多起特大瓦斯爆炸事故，瓦斯的主要成分和天然气相同，试写出发生爆炸的化学方程式______；

（3）天然气是一种非常重要的化石燃料，我国实施的“西气东输”计划输送的就是天然气．我省的部分省市如合肥市即将用上天然气．为了防止燃气泄漏发生危险，可在家中安装报警器（如图），当报警器接触到一定量的泄漏气体时，会发出响声．若家中使用的燃料是天然气，试判断报警器安装的位置应如图中______（填A或B）所示，简述你的判断理由．

（4）若你遇到类似的“井喷”事故，根据你所学的知识以及上文所介绍的有关硫化氢的知识，简述怎样尽量使自己少吸入H₂S，而避免中毒？（只要说出一种行之有效的方法即可）

与胃溃疡发病有关的主要因素有（）。

A.壁细胞总数为正常的两倍

B.胃黏膜屏障破坏，氢离子回渗

C.迷走神经兴奋使胃酸分泌过多

D.十二指肠液返流

E.壁细胞总体减少

减小软式操纵系统弹性间隙的有效措施是：（）

A、采用大直径的钢索

B、采用接头少的钢索

C、采用两条钢索构成操纵回路

D、装配时在钢索上施加预加张力