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问题 选择题

下列关于水的说法中，不正确的是

A．爱护水资源要节约用水、防治水体污染

B．水中某些杂质可用活性炭吸附除去

C．电解水实验可以说明水由氢气和氧气组成

D．每个水分子由2个氢原子和1个氧原子构成

答案

答案：C

题目分析：根据已有知识分析。

A. 爱护水资源既要节约用水，又要防治水体污染，正确；

B. 活性炭具有吸附性，故水中某些杂质（如色素、异味等）可用活性炭吸附除去，正确；

C. 电解水实验可以说明水是由氢氧两种元素组成的，水是纯净物，是一种物质，不可能是由氢气和氧气组成的，错误；

D. 每个水分子是由2个氢原子和1个氧原子构成的，正确。故选C

点评：本题考查的是与水有关的化学知识，难度不大，只要在平时的学习中，注意相关基础知识的积累，即能正确作答。

单项选择题

Questions from 36 to 40 are based on the following passage: There are a lot of “markets”. Some markets are local; you may be willing to compare prices for fruits and vegetables in a few shops in your local area, but you would be unwilling to go across the city to find out more information. Some markets are national. Many firms sell goods across the country. Some markets are global or international. Increasingly, more and more countries are involved in the world economy, whether they know about it or not.However, there are many other markets: labor markets for job seekers, supermarkets for grocery shopping, foreign exchange market, capital market, real estate markets and so on. And we must not overlook the fact that many services such as banking, insurance are also bought and sold on a worldwide scale. But what is a “market” Most people would say, “A market is a place where enough buyers and sellers meet face to face, so that a market price for goods and services can be determined.” However, with rapid growth of telecommunications, it is no longer necessary for buyers and sellers to physically meet to form a market.You may hear the terms “global market” or “global economy”. What do those terms mean to you What do they mean to business today Thanks to the Information Age we are seconds away from the rest of world. Business everywhere recognizes that they can expand their market to anywhere and do business at any time because of the Internet. Now, the Internet is the fastest growing market in the world today, yet buyers and sellers don’t even have to leave their own homes to transact business.In the modern world, a market can take many forms. Generally speaking, a market may be housed in a place, or it may exist only in people’s minds. And a market can be any place or process that brings together buyers and sellers with a view to agreeing to a price.

Which of following statements is True according to the passage（）

A．You are willing to find fruits and vegetables at a lower price all over the country.

B．If a firm sell its products across the country, then it is doing international business.

C．Insurance can not be sold on a worldwide scale.

D．Buyers and sellers can do business without meeting face to face.
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问答题 简答题

公路交通标志的养护应符合哪些要求？
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