跟踪导练（一）1

阅读地带

A

There are about 1，200 species of bats in the world， Swartz says. Some eat fruit. Others eat insects or honey. And just a few drink blood.

Some bats use their eyes to see where things are. Others collect information about their surroundings by bouncing sound off objects and listening to the echoes （回声）.

But what all bats have in common （other than being the only flying mammals in existence） are flexible （灵活的） wings that enable them to change directions quickly. If youve ever seen bats flying with a rush through the air in the early evening， you probably noticed how suddenly they could change directions.

Scientists have long assumed （设想） that bats fly the same way as birds and insects do—with firm， airplane-like wings that connect to the shoulder. The problem with that assumption， however， is that bats arent birds or insects. As mammals， they have more in common with people， horses and dogs than with other flying creatures.

For example， birds have bones which are empty inside， and insects have no bones at all. But most mammals have solid and heavy bones， which would make flying tough.

To solve this problem， bats have evolved strong and heavy bones near their shoulders， where they need more support. Theyve also saved some weight by developing lighter and weaker bones near the tips of their wings. The result is light but strong and very flexible wings.

1. What can we know about all bats from the passage？

A. They can hear sounds with their ears.

B. They are the same as birds in every direction.

C. They have nothing in common with people.

D. They can fly well because of their flexible wings.

2. What can be inferred from the passage？

A. Some bats may be dangerous to people.

B. The scientists assumption is proved to be right.

C. Environment helps bats develop the ability of flying.

D. Bats collect information only by listening to echoes.

3. What can be the best title of the passage？

A. Bats B. Bats Food

C. How Bats Fly D. Flexible Wings

B

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