问题 问答题

根据表中实验内容,设计简单的实验,将实验步骤、现象填入下表.

实验内容实验步骤现象
证明空气中含有水蒸气____________
证明矿泉水是混合物____________

答案

(1)空气中的水蒸气是看不见、摸不着的,因此要验证水蒸气的存在必须要把气态的水变成液态得水或者固态的水;因此实验步骤为:将一只干燥的玻璃片放入冰箱中一段时间后,取出;现象为:干燥的玻璃片上出现水珠.

(2)矿泉水溶解有许多可溶性的矿物质,因此实验步骤为:取蒸馏水少量于洁净的蒸发皿中,加热并用洁净的玻璃棒搅拌;现象为水分蒸发后蒸发皿中出现固体物质.

故答案为:实验步骤:将一只干燥的玻璃片放入冰箱中一段时间后,取出;现象:干燥的玻璃片上出现水珠.

         实验步骤:取蒸馏水少量于洁净的蒸发皿中,加热并用洁净的玻璃棒搅拌;现象:水分蒸发后蒸发皿中出现固体物质.

阅读理解

Americans this year will swallow 15,000 tons of aspirin, one of the safest and most effective drugs invented by man. The most popular medicine in the world today, it is an effective pain reliever. Its bad effects are relatively mild and it is cheap.

For millions of people suffering from arthritis(关节炎), it is the only thing that works. Aspirin, in short, is truly the 20th-century wonder drug. It is also the second largest suicide drug and is the leading cause of poisoning among children. It has side effects that, although relatively mild, are largely unrecognized among users.

Although aspirin was first sold by a German company in 1899, it has been around much longer than that. Hippocrates, in ancient Greece, understood the medical value of the leaves and tree bark which today are known to contain salicylates(水杨酸碱), the chemical in aspirin. During the 19th century, there was a great deal of experimentation in Europe with this chemical, and it led to the introduction of aspirin. By 1915, aspirin tablets were available in the United States.

A small quantity of aspirin (two five-grain tablets) relieves pain and inflammation(炎症). It also reduces fever by interfering with some of the body’s reactions.

小题1:The passage is written to          .

A.suggests us using more aspirin

B.reminds us of the side effects of aspirin

C.gives us a whole view of aspirin

D.discusses the good effects of aspirin小题2:According to the author, aspirin         .

A.is very safe

B.first appeared in 1899

C.can be harmful to children

D.can hardly be dangerous小题3:Generally speaking, the author seems to be           .

A.in favor of aspirin

B.against the use of sapirin

C.not interested in aspirin

D.careful in using aspirin小题4:What is the best title for this passage?

A.How to Use Aspirin

B.Why I Take Aspirin

C.The Most Popular Medicine

D.The Side Effects of Aspirin

单项选择题