问题 填空题

孔雀石的主要成分为Cu2(OH)2CO3,还含有少量Fe、Si的化合物,实验室以孔雀石为原料制备CuSO4·5H2O及CaCO3,步骤如下:

请回答下列问题:

(1)溶液A中的金属离子有Cu2+、Fe2+、Fe3+。上述实验步骤中试剂①为____(填字母,下同),检验溶液B中Fe3+的最佳试剂为____。

a.KMnO4

b.(NH4)2S

c.H2O2

d.KSCN

(2)由溶液C获得CuSO4·5H2O,需要经过加热蒸发、结晶、过滤等操作。除烧杯、漏斗外,过滤操作还要用到的另一玻璃仪器是________,该仪器在此操作中的主要作用是___________。

(3)直接将CO2通入CaCl2溶液中能得到CaCO3沉淀吗? ____________,原因是____________________。

答案

(1)c;d

(2)玻璃棒;引流

(3)不能;碳酸的酸性比盐酸弱

阅读理解

阅读理解。

    The Internet has got into all the fields of our life. We can study and work on it. We can find a job on it.

We can communicate on it. We can treat friends on it. We can buy and sell on it. We can do almost everything

on the Internet, and almost anywhere, anytime.

    However, although the Internet provides services for us, it is silently getting our privacy (隐私) to some

degree. The services on most websites require our personal information. If we want to enjoy these services,

we have to provide much of our information, including our names, sex, addresses, telephone numbers and

sometimes bank accounts (帐户). Because weak network sometimes is unsafe, our information might be open,

stolen or sold. Even sometimes it will be used freely by others.

    Considering (考虑到...) the above mentioned, you must pay attention to the safety when using the Internet.

First, when you need Internet service, you should always look through those big legal (合法的) websites.

Second, if the service requires important personal information, you should think twice before you type it in.

Third, store your own important card key (电子钥匙) and don't tell others easily.

1. According to the passage, we shouldn't _____ by using the Internet. [ ]

A. learn English

B. look for jobs

C. chat with friends

D. give our friends' information to others

2. The 2nd paragraph mainly tells us _____. [ ]

A. what we can do on the Internet

B. some network isn't safe so that our personal information is known or used by others

C. we have to enjoy the services of the Internet

D. using the Internet is a waste of time

3. The underlined word "it" refers to _____. [ ]

A. the information

B. the name

C. the telephone number

D. the bank account

4. Which of the following ways is correct to protect our information on the Internet?

    a. Surf the safe Web.

    b. Think over and over before typing it in.

    c. Don't chat with friends on line.

    d. Don't use your key easily. [ ]

A. a,b,c.

B. b,c,d.

C. a,b,d.

D. a,c,d.

5. What can we learn from the passage? [ ]

A. From now on, we must pay attention to the safety of the information on line.

B. Remember never use the ID card on the Internet.

C. Never use the Internet in the future.

D. Don't believe others if you don't know them.

单项选择题