问题 选择题

将钢丝绒置于浮在水面的表面 皿中(如图),用烧杯罩住表面皿,并使杯口没入水中,经过一段时间,可发现烧杯中的液面慢慢上升.产生此现象的原因是(  )

A.因水凝结在烧杯中

B.因钢丝绒和烧杯中的氧气起反应

C.因钢丝绒会放出一种可溶于水的气体

D.因烧杯中的氧气溶于水

答案

铁生锈消耗烧杯中的氧气,使得烧杯内压强降低,在外界大气压的作用下,烧杯内的液面上升;

故选B.

多项选择题
阅读理解

Consumers are being confused and misled by the hodge-podge (大杂烩) of environmental claims made by household products, according to a “green labeling” study published by Consumers International Friday.

Among the report’s more outrageous (令人无法容忍的) findings, a German fertilizer described itself as “earthworm friendly”, a brand of flour said it was “non-polluting” and a British toilet paper claimed to be “environmentally friendlier”.

The study was written and researched by Britain’s National Consumer Council (NCC) for lobby group Consumer International.It was funded by the German and Dutch governments and the European Commission.

“While many good and useful claims are being made, it is clear there is a long way to go in ensuring shoppers are adequately informed about the environmental impact of products they buy,” said Consumers International director Anna Fielder.

The 10-country study surveyed product packaging in Britain.Western Europe, Scandinavia and the United States.It found that products sold in Germany and the United Kingdom made the most environmental claims on average.

The report focused on claims made by specific products, such as detergent (洗涤剂), insect sprays and by some garden products.It did not test the claims, but compared them to labeling guidelines set by the International Standards Organization (ISO) in September, 1999.

Researchers documented claims of environmental friendliness made by about 2,000 products and found many too unclear or too misleading to meet ISO standards.

“Many products had specially-designed labels to make them seem environmentally friendly, but in fact many of these symbols mean nothing,”said report researcher Philip Page.

“Laundry detergents made the most number of claims with 158.Household cleaners were second with 145 separate claims, while paints were third on our list with 73.The high numbers show how confusing it must be for consumers to sort the true from the misleading.” he said.

The ISO labeling standards ban vague or misleading claims on product packaging, because terms such as “environmentally friendly” and “non-polluting” cannot be tested.“What we are now pushing for is to have multinational corporations meet the standards set by the ISO.” said Page.

1.According to the passage, the NCC found it outrageous that ____.

A.all the products surveyed claim to meet ISO standards

B.the claims made by products are often unclear or misleading

C.consumers would believe many of the manufactures’claim

D.few products actually prove to be environmentally friendly

2.A study was carried out by Britain’s NCC to ____.

A.find out how many claims made by products fail to meet environmental standards

B.inform the consumers of the environmental impact of the products they buy

C.examine claims made by products against ISO standards

D.test the guidelines set by the International Standards Organization

3.What is one of the consequences caused by the many claims of household products?

A.They are likely to lead to serious environmental problems

B.Consumers find it difficult to tell the true from the false

C.They could arouse widespread anger among consumer

D.Consumers will tend to buy products they don’t need

4.It can be inferred from the passage that the lobby group Consumer International wants to ____.

A.make product labeling satisfy ISO requirements

B.see all household products meet environmental standards

C.warn consumers of the danger of so-called green products

D.prove the efforts of non-polluting products