第三部分阅读理解（共20小题；每小题2分，满分40分）
阅读下列短文，从每题所给的四个选项（A、B、C和D）中，选出最佳选项。
Spiders are actually useful. They do not harm plants, as some people think. Instead, they protect plants by controlling insects. If you see spiders in a garden, it doesn’t mean the garden is unhealthy. It means the spiders are helping the garden stay healthy.
If you spend some time watching spiders, you may be surprised by what you see. There are many wonderful webs. They may perform skillfully on their thin silk threads. However, some spiders spin (织) no webs at all. They follow insects on the ground with all the skill and cruelty of a tiger hunting big game.
Scientists have named about 30,000 species of spiders, but they think this is only one-fourth of all the different kinds of spiders in the world. In most species, people can easily tell the female spider from the male because the female is much bigger. For example, the female black widow (黑寡妇) weighs about one hundred times as much as the male.
Female spiders lay eggs. After hatching (孵), most spiders live less than a full year, but some don’t. Tarantulas (狼蛛) do not become adults until they are 10 or 11 years old. Female tarantulas often live an extra 10 years! The baby spiders that hatch from the eggs are called spiderlings.
56. The underlined in Paragraph 2 part “a tiger hunting big game” refers to “______.”
A. laying eggs B. hatching baby spiders
C. spinning webs D. catching insects
57. How many kinds of spiders are there in the world according to the passage?
A. About 30, 000. B. About 60, 000. C. About 90, 000. D. About 120, 000.
58. What can we know from the passage?
A. If there are spiders in your garden, it means it is unhealthy.
B. All spiders can spin webs.
C. Normally, a male spider is smaller than a female one.
D. All spiders can live 10 or 11 years after hatching.
59. What will be probably talked about after the last paragraph?
A. The way spiders spin webs. B. Something about spiderlings.
C. How the spiders protect plants. D. The way spiders stay healthy.