试题与答案

Ca3(PO4)2、CaHPO4均为难溶于水的白色固体。某同学向Na2HPO4溶

题型:实验题

题目:

Ca3(PO4)2、CaHPO4均为难溶于水的白色固体。某同学向Na2HPO4溶液中滴加CaCl2溶液至恰好反应,生成了白色沉淀。试设计一个简单的实验方案,来证明所生成的白色沉淀是Ca3(PO4)2还是CaHPO4。 

实验原理:______________________________

实验用品及试剂:试管、胶头滴管、______________________        _________

实验步骤、现象、结论(可不填满)

①_________________________________;②_______________________________;

③_________________________________;④_______________________________。

答案:

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题型:阅读理解

We use an average of 158 liters of water a day in Britain, for which we pay a bargain price of 28p a liter, but much of this is just cash down the drain, according to water companies.

Most are campaigning to cut the amount we use. And the frontline weapon in their campaign is the water meter (计量器). They want us all to have one and one company is seeking powers to make this compulsory.

The Government is anxious for us to use less water, too. Elliot Morley, the Environment Minister, says he is impressed by the savings when a meter is installed. In most homes, consumption drops by 20 percent.

He also thinks consumers get a good deal from meters. He said, “Most people would find that they would either be exactly the same or better off with water meters and it is a fairer way of paying for water.”

At present, only 25% of households have meters and most of those are in East Anglia. They are installed by water companies, and households then have about £43 added to each bill to cover the cost of installing and reading the meter.

Barrie Clarke, a spokesman for Water UK, said, “We want everyone to be more water wise—to think about the amount of water they use. But with our climate change and different weather patterns, over time it will make economic and environmental sense to think how we use water. This may mean meters.”

Mr. Clarke believes the easiest way to save water is to use less in the garden. In one hour, a sprinkler uses the same amount of water as the average family of four uses in a day—about 632 liters. He said that gardeners should water in the evening so that it dose not evaporate in the heat of the day and that every household should have a water butt to collect rainwater for use in the garden.

小题1:Which of the following is NOT the advantage of installing water meters?

A.Water consumption drops.

B.It’s fairer to pay for water.

C.They’re installed for free.

D.People are more water wise.小题2:The passage implies that ________.

A.water meters are welcome by British people

B.people will be better off with water meters

C.everyone has become wiser to use water now

D.saving water is both good to economy and environment小题3:How many liters of water does an average family of four use in a day after installing a meter in Britain?

A.about 126 liters

B.about 158 liters

C.about 506 liters

D.about 632 liters小题4:The underlined word “evaporate” in the last paragraph means _________.

A.change into steam and disappears

B.absorb the heat of the day

C.sink into the soil

D.turn into ice小题5:According to Mr. Clarke, some good ways to save water are as follows EXCEPT ________.

A.using less on the garden

B.using a sprinkler

C.watering in the evening

D.gathering rainfall for garden use

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