收集气体的常用方法有:①向上排空气法;②向下排空气法;③排水法。已知在标准状况下

题型:选择题

问题:

收集气体的常用方法有:①向上排空气法;②向下排空气法;③排水法。已知在标准状况下,甲烷的密度是空气的5/9,且难溶于水,那么,收集甲烷气体可用的方法有[ ]

A.①②

B.①③

C.②③

D.①

考点:实验室制取和收集气体的思路
题型:选择题

阅读理解。

       It was Mother's Day. He was driving his new car and he saw the colorful flower shop along the road,

  he stopped his car, got out and took a closer look at some of the flowers on display.

       He thought about his loving mother who lived two hundred miles away. He chose some pink roses

  and asked the shopkeeper to post them to his mother at the same day. Just before he got into his car, he

  noticed a small, cute girl standing next to the shop. She was counting the money in her hand. She seemed

  a little upset.

       He went up to her and asked, "Can I help you?"

       She replied in a sad voice, "I want to buy some red roses for my mother. But I don't have enough

  money."

       He smiled and bought some red roses for her. While leaving the shop, he offered her a ride. She

  showed him the way, which finally led to a cemetery. She got off his car, gave him a hug (拥抱) and

  said, "Thank you, Uncle." Then she ran to her mother's grave (坟墓).

       The man was speechless for a minute. He drove back to the same flower shop at once. He took the

  pink roses and drove two hundred miles to meet his beloved mother.

       He handed over the flowers to his mother, gave her a big hug and said, "I love you, Mama."

       His mother was very excited.

1. The story happened _____.

A. on the day before Mother's Day      

B. on Mother's Day

C. on his mother's birthday          

D. on a cold winter morning

2. The man asked the shopkeeper to post the flowers to his mother in order to _____.

A. give his mother a big surprise    

B. make his mother miss him

C. show his love to his mother        

D. tell his mother it's Mother's Day

3. The girl was a little upset because _____.

A. she couldn't see her mother

B. the shopkeeper didn't sell her red roses

C. she couldn't afford the red roses for her mother

D. her mother died

4. The underlined word "cemetery" means _____.

A. 公园

B. 会场

C. 纪念馆  

D. 墓地

5. What is the correct order of the following events?

a. The man asked the shopkeeper to post the roses.

b. The man drove the girl to her mother's grave.

c. The man met a girl outside a flower shop.

d. The man was driving along the street.

e. The man drove home to meet his mother,

A. d-b-c-e-a    

B. d--a-c-b-e    

C. a-e-d-c-b  

D. c-d-a-e-b

题型:选择题

影响局部麻醉药在硬膜外腔扩散的因素除外()。

A.局部麻醉药的容积和浓度

B.局部麻醉药注射的速度

C.血容量不足

D.身高

E.下腔静脉受压

题型:选择题

简述埃里克森的人格发展阶段论。

题型:选择题

恩格斯称赞法国启蒙思想家“都是非常革命的”,是因为他们()

A.主张君主立宪制

B.主张共和制

C.反对专制王权和等级制度

D.主张取消私有财产

题型:选择题

不属于化学性爆炸事故的是()发生的爆炸。

A、焊接制冷系统时

B、氨气遇明火

C、使用惰性气体试压时

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