问题 填空题

今年“中国水周”活动的宣传主题为“发展水利,改善民生”.下面关于水的认识

(1)水______(填“属于”或“不属于”)六大类营养素之一;

(2)最近我国西南地区出现百年罕见干旱,1000多万群众饮水受到严重影响,许多乡村群众从150多米深抽出地下水,但抽出的水出现浑浊、有异味等不适合直接饮用的硬水,请你帮助群众将地下水进行简单净化,以解用水危机:

①可以采用______区分硬水和软水,可以通过______的方法降低水的硬度.

②为将浑浊的地下水处理成较澄清,可向浑浊的地下水加入______,使杂质沉降,同时还可以通过______将沉降的不溶杂质除去;

③还可以加入______吸附地下水中的异味,最后利用熟石灰调节水的酸碱度,从而得到澄清、无异味基本可以饮用的水.

答案

(1)水属于六大类营养素之一;故填:水.

(2)①向水中加入肥皂水时,如果产生的泡沫较多,是软水;如果产生的泡沫很少,是硬水;加热煮沸时,水中的钙离子和镁离子能够以沉淀的形式析出,从而降低水的硬度.故填:肥皂水;加热煮沸.

②明矾具有吸附性,能够吸附水中的悬浮物;过滤可以把不溶于水的物质除去.故填:明矾;过滤.

③可以加入活性炭吸附地下水中的异味,最后利用熟石灰调节水的酸碱度,从而得到澄清、无异味基本可以饮用的水.故填:活性炭.

阅读理解

 阅读理解。

     Most children don't enjoy doing housework. They like playing computer games rather than cleaning

the rooms. But in Australia, Jim and Robert's mother, Mrs Black, has good and proper methods to get their

children to do housework.

     Here is an example.

     "Mum, have you worked out next week's housework? Let Jim and me choose the cards I can't wait. It's

fun!"

     When Robert shouted out, his mother had already put all the cards on their big table. On the cards, there

are some words like these, "sweep the floor, clean your bedroom, help mum cook, wash vegetables, make

beds, feed the fish, cut the wood, clean the bathroom" and many others, Jim and Robert chose two cards for

each day from Monday to Friday. Then they would hang them on the week day task board. Jim likes to clean

the bathroom, so he picked up the card "clean the bathroom". Robert loves to make the bed so he picked up

his favorite card. Jim again picked up "wash vegetables" and Robert chose"feed the fish". Soon the two boys

were happy to take away all the cards

     To help the children do housework, their mother thought hard and came up with this idea. Of course, the

parents did the housework on the weekends and left Jim and Robert two days free.

1. From the passage we know that most children like ________.

A. doing housework

B. playing computer games

C. playing cards

D. doing housework

2. Jim and Robert chose card for the weekdays from Monday to Friday.

A. two

B. four

C. eight

D. ten

3. Jim likes to ________.

A. clean the bathroom

B. make the bed

C. feel the fish

D. sweep the floor

4. The underlined phrase "came up with" probably means "________".

A. looked at

B. gave up

C. thought of

D. believed in

5. Who did the housework on the weekends?

A. Jim

B. Robert

C. The parents

D. The whole family

多项选择题