手工电弧焊工艺过程。

实验室常用气体的发生和收集装置如图所示，回答下列问题：

（1）指出标号①的仪器名称______；

（2）制取二氧化碳气体，应选择上图中的______组合（填字母序号）；

（3）12.5克石灰石（碳酸钙的质量分数为80%，杂质不与酸反应）中，加入足量的稀盐酸充分反应，可制得二氧化碳多少克？

（4）用上述方法收集的二氧化碳可能会有空气，请你设计一个简单的实验来证明______（画图或文字说明均可）．

在流行病学研究中，相对危险度主要应用于（）

A.现场试验

B.病例对照研究

C.现况研究

D.生态学研究

E.队列研究

某厂房平面宽度为80m，外搭脚手架的宽度为3m，采用轨距为4.2m的塔式起重机施工。塔式起重机为单侧布置，其最大起重半径不得小于( )m。

A．42.8

B．45.6

C．85.6

D．86.8

“Fire! Fire!” What terrible words to hear when one wakes up in a strange house in the middle of the night! It was a large, old, wooden house and my room was on the top floor. I jumped out of bed, opened the door and stepped outside the house. There was full of thick smoke.

I began to run, but as I was still only half-awake, instead of going towards the stairs I went in the opposite direction. The smoke grew thicker and I could see fire all around. The floor became hot under my bare feet. I found an open door and ran into a room to get to the window. But before I could reach it, one of my feet caught in something soft and I fell down. The thing I had fallen over felt like a bundle of clothes, and I picked it up to protect my face from the smoke and heat. Just then the floor gave way under me and I crashed to the floor below with pieces of burning wood all around me.

I saw a doorway in fire, then I put the bundle over my face and ran. My feet burned me terrible, but I got through. As I reached the cold air outside, my bundle of clothes gave a thin cry, I nearly dropped it in my surprise. Then I was in a crowd gathered in the street. A woman in a night-dress and a borrowed man’s coat screamed as she saw me and came running madly.

She was the Mayor’s wife, and I had saved her baby.

小题1:When the fire arose in the middle of the night, the author was _______.

A．at home

B．sleeping

C．sitting in bed

D．both A and B小题2:The author saved the baby _____.

A．because he was very brave.

B．because he liked the baby very much.

C．but he just happened to save it.

D．because it was the Mayor’s baby.小题3:He ran in the wrong direction because he _______.

A．was a stranger there

B．could see nothing

C．was not completely awake

D．Both A and C小题4:He put the bundle over his face and ran in order to ______.

A．save the baby

B．call for help

C．protect his face

D．run quickly小题5:Form which group of words, we can learn the fire took place out of people’s surprise?

A．old and wooden house, a bundle

B．crashed to, fell down

C．terrible, half-awake

D．bare feet, a borrowed man’s coat

新版票据的票号有两排，其中若第一排票号为”10300052”，那此票为（）。

A.现金支票

B.转账支票

C.银行承兑汇票

D.清分机本票