阅读理解。
Many plants and animals live together, and they depend on each other. They are usually very
different from their sharing partner, and yet all live easier lives because of each other. It is nature's
idea of sharing.
An example of this is the shark and pilot fish. The pilot fish is a little guy and he would be
helpless if he hung around by himself in the great ocean. But his smartness makes up for his size.
He cleverly swims along beside the shark and when the shark eats, the pilot fish gets the leftovers.
The shark also benefits from this relationship. The pilot fish cleans food scraps (碎屑) and insects
from the shark's skin.
Another example is the sea anemone (海葵) and striped clown fish. The sea anemone looks
like a flower but contains poisonous cells. When small fish swim into it, the anemone traps and
paralyzes (使麻痹) them. However, the striped clown fish is able to swim into the poisonous
anemone without being harmed. To pay for his safety, the clown fish brings food to the anemone.
He also guides other fish into the anemone's deadly trap.
Large mammals such as the ox, antelope and African buffalo form such a relationship with the
oxpecker. They provide daily meals to the bird that eats insects. The various large mammals act
as a restaurant with a varied menu for the oxpecker. What do they get in return from the bird?
Free beauty treatments!
Some plants live together in a beneficial relationship. Fungus (菌类) does not have chlorophyll
(叶绿素) that plants need to make food. However, the green alga (海藻) does contain chlorophyll.
It is, therefore, able to feed the fungus along with itself. But nothing is free! The fungus repays it
by protecting the alga. Since it takes in and stores water, it can provide the alga with an unending
water supply.
1. Why does the pilot fish swim along beside the shark?
A. To do the cleaning for the shark.
B. To help the shark to get food.
C. To get food and protection.
D. To find some insects.
2. In order to repay the sea anemone, the striped clown fish _____.
A. paralyzes animals for the sea anemone
B. leads other fish into the anemone
C. harms other fish with poison
D. protects the anemone's cells
3. What do we know about oxpeckers?
A. They are particular about what they eat.
B. They are mostly seen near restaurants.
C. They stay away from large mammals.
D. They feed on small insects.
4. What is the passage mainly about?
A. Nature's examples of sharing.
B. Places where sharing exists.
C. The relationship of living things.
D. Animals that depend on each other.