问题 选择题

下列说法中正确的是(  )

A.熵减的吸热反应可能是自发反应

B.需要加热的化学反应,生成物的总能量一定高于反应物的总能量

C.使用催化剂既不会改变反应的限度又不会改变反应的焓变

D.已知2C(s)+2O2(g)2CO2(g) ΔH1;2C(s)+O2(g)2CO(g) ΔH2,则ΔH1>ΔH2

答案

答案:C

化学反应自发地向熵增大的方向进行,故A错误;B项,反应条件与反应的热效应无关,错;D项焓变是负值,所以ΔH1<ΔH2,故错误。

阅读理解

In much society, there is often greater acceptance of light skin than dark skin; Light skin may be seen as a mark of beauty, intelligence and success. These beliefs can lead to social pressures even within the same group, if some members are darker than others.

The result is that skin lightening has become very common across Africa, Asia and other areas of the world and more people with dark skin are using skin-lighting products, even if it means they may face health risks. They believe that having whiter skin will improve the quality of their lives. Many people think they will have a better family. Or they want to look like what their society generally considers beautiful.

Some beauty care(美容) products and soaps contain chemicals that make skin lighter. However, some of the chemicals are extremely dangerous. The chemicals in the products block and break down the natural barrier(障碍) to protect against sunlight. Then the skin can become thick and discolored. Usually the person will use more of the product in an effort to correct the problem, which just makes things even worse. Doctor Ly says some chemicals are so dangerous that they may lead to blackened fingernails, infections(感染) and serious skin damage.

And these are not the only problems. Experts say some people who change their skin color suffer emotional damage. They feel regretful and sad. They feel that instead of risking their health, they should have learned to live and accept their skin color as it was.

小题1: What’s the result of the wrong understanding of darker skin?

A.Many people with dark skin try to make their skin whiter.

B.Many people with whiter skin live a better life than others.

C.People with darker skin try to marry people with light skin.

D.People with darker skin try to protect themselves against social pressures.小题2: The third paragraph is about         .

A.some medical effects that skin-lightening products have brought about

B.the mental damage that skin-lightening products have caused

C.the physical damage that skin-lightening products have caused

D.the causes why skin-lightening products can make skin whiter小题3: Why are chemicals in beauty care products dangerous?

A. They can damage the skin’s color producing progress.

B. They can control people’s emotions and feelings.

C. They can make the fingernails and skin black.

D. They make more people decide to change their skin colors.

ACAB What would be the best title for the passage?

A. Different Colors of Skin              B. The Dark Side of Skin Lightening

C. What Is Beauty?                     D. Light Skin or Dark Skin?

单项选择题