副车架是装在汽车底盘大梁上的附加车架，其作用一是布置和承载上车全部构件，二是在作业时

阅读理解。

   It was Mother's Day. John was so busy with his work that he couldn't go back home. When he passed

by a flower shop in the evening, an idea came to his mind, "I'll send Mum some roses. "While John was

picking his flowers, a young man went inside.  "How many roses can I get for only five dollars, madam?"

he asked. The assistant was trying to tell him roses were as expensive as forty dollars a dozen( 一捆).  

Maybe he would be happy with carnations

    "No, I have to have red roses," he said.  "My mum was badly ill last year and I didn't get to spend much time with her.  Now I want to get something special, it has to be rose as rose is her favorite. "

     After hearing it, John said he would pay the rest of the money for the young man.  Moved

by both of them, the assistant said, "Well, lovely young men, thirty dollars a dozen, only for you. " Taking

the roses, the young man almost jumped into the air and ran out of the shop.  It was well worth twenty-five dollars that John paid to see the exciting moment. Then John paid for his dozen of roses and told the

assistant to send them to his mother.

     As he walked out, he felt nice. Suddenly he saw the young man crossing the street and going into a

park. But soon John realized it was not a park but a cemetery(墓地). Crying, the young man carefully put down the roses, "Mum, oh, Mum, why didn't I tell you how much I loved you? God, please help me find

my mum and tell her I love her. "

     Seeing this, John turned and quickly walked to the shop. He would take the flowers home himself.

1. The assistant tried to ask the young man to buy carnations instead of roses because

A. carnations were nicer than roses          

B. roses were saved for John

C. roses were more expensive than carnations

D. carnations were special flowers for Mother's Day

2. John spent         altogether(总共)  in the flower shop that day.       

A. $5          

B. $ 25        

C. $ 30        

D. $ 65

3. The young man cried at the cemetery because he               .       

A. had spent all his money on the roses

B. wasn't able to tell his mother he loved her himself

C. felt sorry to ask John to pay for his flowers

D. hadn't got enough money for his sick mother

4. At last John changed his mind and went home because he wanted to             .        

A. tell his mother he loved her himself

B. ask his mother for more money

C. tell his mother the young man's story

D. ask his mother if she likes roses

5. The writer writes the passage in order to tell us "             .

A. Buy roses for your mother when she is ill

B. Let your mother know how much you love her

C. Work hard to get more money for your mother

D. Send your mother flowers on Mother's Day

碳纤维是一种强度比钢大，密度比铝小，比不锈钢耐腐蚀，比耐热钢耐高温，又像铜那样导电，具有许多宝贵的电学、热学和力学性能的新型材料．现在，人们还不能直接用炭或石墨来抽丝制取碳纤维．目前所采用的方法是将有机纤维跟塑料树脂结合在一起，放在惰性气体中，在一定压强下强热、碳化而得碳纤维．请回答下列问题

（1）制取碳纤维的过程属于______变化．

（2）在惰性气体中制取碳纤维的原因是______．

以下实验操作正确的是（　　）

A．用量筒量取5.0mL浓硫酸并直接在量筒中稀释

B．称量NaOH固体时，将药品直接放在托盘上

C．给烧瓶里的液体加热时，垫上石棉网

D．用嘴吹灭燃着的酒精灯火焰

住房公积金管理委员会的主任（）

A.应当由具有社会公信力的人士担任

B.是管理委员会的法人代表 

C.应当由政府负责人担任

D.应当由人大代表担任

根据《华润置地商业物业服务标准》要求，工程管理类责任内中上及死亡事故为0，责任内轻伤事故应（）。

A.低于1

B.不高于1

C.低于2

D.不高于2