问题 选择题

10.下列分离、提纯、鉴别物质的方法正确的是( )

A 用丁达尔效应鉴别Fe(OH)3胶体和FeCl3溶液

B 用过滤的方法除去NaCl溶液中含有的少量淀粉胶体

C 用溶解、过滤的方法提纯含有少量BaSO4的BaCO3

D 用加热、蒸发的方法可以除去粗盐中的CaCl2、MgCl2杂质

答案

答案:A

胶体和溶液都能透过滤纸,应该用渗析法,B不正确。C不正确,两种物质均不溶于水。D不正确,直接加热除不去杂质,应该用沉淀法。所以正确的答案是。

填空题
阅读理解

     Parsley (欧芹)  is an ancient green and a respected addition to many foods. But at other times, its

job is just to make a mealtime plate look pretty. Poor parsley, valued for its looks, then is thrown away.

Yet parsley is a good source of vitamins and other nutrients. The taste is a little strong for some people,

but others chew on parsley to freshen their breath.

     Curly parsley is the king that often ends up being used just for appearance. Flatleaf parsley is easier

to work with for cooking. This kind is often called Italian or French parsley. Do you know about a third

kind of parsley? Hamburg parsley has flat leaves that can be used for the same purposes as other parsley. But hamburg parsley has a large root which is used as a vegetable to add flavor to soups.

     Parsley is used in foods such as tabouli, a traditional Lebanese salad and is often served with lamb,

fish and beef dishes. Parsley is a herb if you use just the greens.If the root is used, then parsley is

considered a vegetable.

     Some gardeners suggest that to get the besttasting parsley, you should plant new seeds every year.

You can get parsley to grow faster by pouring warm water over the seeds. Leave the seeds in the water

overnight. Then you can grow them in containers indoors or plant them outside. Parsley grows best when

temperatures are below twentyone degrees Celsius. It likes to grow in sunny places. The seeds need rich

soil. Plant the seeds about fifteen to twentyfive centimeters apart. Water them regularly during the first

month. After that, parsley does not need very much water. You can harvest parsley by cutting most of

the plant or leave more of the plant in the ground for a second crop.

1. From the passage we can learn that________.

A. people don't like parsley's strong taste at all

B. people don't attach great importance to parsley's value

C. parsley has been widely planted in the world

D. only ancient people used parsley as an addition

2. Which of the following can be the best title for the passage?

A. The Planting of Parsley  

B. To Parsley's Regret

C. Parsley  

D. The Use of Parsley

3. It seems________to the writer that parsley is valued for its looks.

A. regretful  

B. unbelievable

C. confusing  

D. doubtful

4. The last paragraph mainly deals with________.

A. how to use parsley

B. whether people like parsley

C. how to plant parsley

D. how the author feels about parsley