题目内容：

Many people believe that yellowing and wetness are the greatest enemy of stamps. In fact, stamps are afraid of not only wetness, but also light and dirty things. People protect their stamps in several different ways.

To protect stamps, we should never touch the stamps with our hands. This avoids moving dirty things onto them. Stamp tweezers(镊子) should be used in all conditions.

Stamps are printed things. The color will slowly disappear if the stamps are put in the light for a long time. So we should not put stamps in the light for long. Direct sunlight must be avoided as well.

Wetness is an important problem for stamps. Some collectors will put stamps in separate plastic (塑料) bags. However, it is possible that some stamps have taken in some water from the air before they are put into the plastic bags. Stamps become yellow easily and rapidly after they take in wet air. To protect the stamps, some people also put the stamps into a special room which has a machine to keep the air cool and dry. However, not many people can afford that.

To_keep_stamps,_stamp_collectors_usually_put_them_under_plastic_covers. It is a common and simple way. This helps because the plastic cover keeps the stamps off the wet air. It also stops the fingers from touching the stamps.

Some collectors prefer to store stamps inside a plastic box with desiccants(干燥剂)．However, we should take care not to let the stamps touch the desi­ccants. On top of that, don't take your stamps out on a wet day.

1题完成句子；2～3题简略回答问题；4题找出并写下全文的主题句；5题将文中画线句子译成汉语。

1.One way to protect stamps is that we should never touch them ________________．

2.What will disappear if we put the stamps in the light for long?

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3.When do stamps become yellow easily and rapidly?

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4.________________________________________________________________________

5.________________________________________________________________________