阅读理解：
Matter exists in one of three states: solid, liquid
or gas. Air is in the gaseous state. It is not in the
solid or liquid state. Solids are rigid（坚硬的）and have
definite form while air is a colorless, tasteless, invisible
gas, in fact a mixture of gases, which surrounds the
planet earth. It is everywhere on the planet. An “empty”
drinking glass and an “empty”room, to give two examples,
are not really empty. Each is filled with air. When the
glass is filled with water, the water pushes the air
out of the glass.
Air, as a gas, has no definite shape, but because
it is matter which diffuses, it takes up space. It is
easy to prove that air is something that takes up space.
Stuff a dry handkerchief into the bottom of a glass so
that it will not fall out when the glass is turned upside
down. Push the upside down glass, held straight up and
down, into a jar of water till the glass is completely
covered. When the glass is taken out of the water, the
handkerchief will be dry. The air inside the glass took
up space and kept the water from coming in.
1．From the passage we can infer ______.
A．water is rigid and flows
B．coal is rigid and takes the shape of the container
C．oxygen is a gas which has a definite form
D．steam diffuses and has weight
2．The writer tells us that ______.
A．all the containers are filled with air
B．an invisible gas is a mixture
C．air fills the container
D．all of the gases are tasteless
3．When you perform the experiment, you should first
________.
A．press a handkerchief tightly into the bottom of a
glass
B．dip a handkerchief carefully into a glass
C．tie a handkerchief firmly in a glass
D．blow a handkerchief quickly into the bottom of a glass
4．Which of the following pictures gives us the correct
result?
答案与提示：
1．D 这道题要求学生通读全文，了解其大意，通过整篇对气体的主要陈述得知，虽然它看不见，无色，无味，无形状，但它实实在在地存在于我们周围，而且有重量。故答案为D。
2．C 这是一个判断题，考察学生的观察推理能力。B和D是早已人人尽知的事实，不是作者告诉读者的，而作者对“empty”这一词使用了引号，说明气体存在于各个容器内，无处不在。而A的结论“所有的容器充满的都是空气”太绝对了。
3．A 这是一个细节题，需要学生根据上下文知道“stuff”的意思，以及手帕的放法。下面有一句“...so
that it will not fall out when the glass is turned
upside down.”表示“...以至于当玻璃杯倒置的时候，手帕不会掉出来。”由此得知，手帕必须紧紧地贴在玻璃杯底部。
4．C 根据文章对这一实验的描述过程“放手帕到玻璃杯中——再将玻璃杯倒置——放入水中——拿出玻璃杯”。所以C图符合这一过程。
