问题 填空题

在H、O、C、S、Cl、Na、Ca七种元素中选择适当的元素组成符合下列要求

的物质.请将其化学式填入空格中.

(1)可用于改良酸性土壤的碱:______

(2)无色、无味的剧毒气体:______

(3)焙制糕点所用发酵粉的主要成分之一:______

(4)能使紫色石蕊试液变红的化合物:______(任填一个)

答案

(1)以上元素可组成的碱有NaOH、Ca(OH)2,能用来改良酸性土壤的碱是Ca(OH)2

(2)一氧化碳是无色无毒的气体,一氧化碳的化学式为CO;

(3)可用作发酵粉和治疗胃酸过多症的是小苏打,化学是为NaHCO3

(4)石蕊试液遇酸性溶液变红,以上元素可组成的酸有HCl或H2SO4

故答案为:(1)Ca(OH)2

(2)CO;

(3)NaHCO3

(4)HCl或H2SO4

完形填空

I was a single parent with my son. Two jobs allowed me an apartment, food, and child care payment. Little money was left over for clothes,   1   I kept us nicely dressed. Loving    2    , I bought for myself beautiful reds and oranges, and greens and pinks. And quite often I wore them in mixtures, which, against the usually correct way, brought   3   to the eyes of people who could not avoid    4     me.

I went to my son’s    5     frequently. And he would always come and greet me and my colorful clothes.    6    , when my son was six, he told me    7    that he had to talk to me.

“Mother, do you have any sweaters that    8    ?”

I said, “No, I don’t.”

“Oh, I wish you did.     9    you could wear them to my school.” Then he continued, “Mother, could you please    10    come to school when they call you?” Then I realized that my dress was a(n)    11    to him.

I learned to be a little more careful to    12      causing him displeasure. As he grew older and more confident, I gradually    13     to my particular way of dressing. I was happier when I chose and created my own    14    .

I have lived in this body all my life and know it much   15    than any fashion designer. I think I know what looks good   16    me.

17     is important to mention because many people are imprisoned by powerful principles on the    18    way of dressing. Those decisions made by   19     are not truly meant to make your life better. Seek the fashion which truly suits you. You will always be in fashion if you are    20    to yourself.

1. A. but                B. and             C. or                  D. because

2. A. shapes           B. styles          C. colors            D. tastes

3. A. envy            B. appreciation   C. disappointment      D. surprise 

4. A. recognizing       B. admiring      C. accepting         D. noticing

5. A. office            B. home         C. school            D. lab

6. A. However         B. Meanwhile     C. Otherwise         D. Therefore

7. A. proudly            B. jokingly         C. seriously            D. curiously

8. A. cost             B. work           C. fit              D. match

9. A. Even if             B. As if             C. So that             D. In case

10. A. only            B. still             C. once            D. ever

11. A. wonder          B. surprise        C. embarrassment    D. honor

12. A. practice           B. remember         C. mind              D. avoid

13. A. turned           B. returned        C. escaped          D. took

13. A. fashion            B. sweater           C. color             D. tradition

15. A. better            B. worse           C. more           D. less

16. A. in               B. on               C. with          D. of 

17. A. Dress           B. Money           C. Principles      D. Designers

18. A. experienced      B. proper           C. formal          D. simple

19. A. me             B. yourself          C. others          D. ones

20. A. true             B. serious          C. practical        D. responsible

单项选择题