四、短文填空
One day, Kelly's father invited her to visit an ocean park and dive(潜水)with him. When diving, the beauty of the underwater world surprised Kelly. Kelly saw how the plants and animals lived together 1. (perfect). She took many photos with an underwater camera. It was the most exciting experience in her life. But she also saw many coral reefs in danger because of 2. (pollute).
After lunch, Kelly turned to her father. "I will do something 3. (meaning)for the coral reefs from now on," she said. "They need our help."
When she went back to school, Kelly 4. (speak)to her class about coral reefs, "Coral reefs are 5. important part of our ocean. 6. , many of them are in great danger. My father told me that coral reefs keep our beaches safe 7. powerful waves(海浪)and they are home to many kinds of animals."
When she got home, Kelly put up a notice on the internet. It read, "The ocean is 8. (call)for help. Please help the ocean's coral reefs. Keep 9. (they)safe and healthy." In three weeks, thousands of people liked Kelly's notice. Within one year, some laws were passed by the government to protect the coral reefs. More and more people took part in the voluntary activities.
"You have made a 10. (different), Kelly," said her father. "Thank you! The coral reefs of the world thank you."

五、阅读短文，回答问题
A forest is like a football group. It sounds unusual, but it's true. Each player does an important job, but they can't win by themselves, so they work together. The same is true of all plants and animals in a forest. They depend on each other to live. We call this an ecosystem.
There are three jobs in an ecosystem: producer, consumer and decomposer. The trees in the forest produce food by themselves. Giraffes themselves can't make their own food, so they consume or eat the trees' leaves. But sometimes hungry lions or other animals eat giraffes. When animals die, their bodies become part of the soil(土壤)and air to help the forest grow. So the ecosystem can keep on going.
Ecosystems come in lots of kinds and sizes. A backyard or even a big sea can be an ecosystem. The key thing is that an ecosystem has to be balanced. If there weren't animals to eat giraffes, giraffes would eat too many leaves. This wouldn't be good for the trees, and this would make it difficult for giraffes to find food. Different weather and natural disasters can change the ecosystems. Human activities like cutting down the trees and hunting can also bring problems.
Ecosystems are everywhere. They play an important part in our life. It is necessary for us to do what we can to keep them working well.

1. How many jobs are there in an ecosystem?

2. If the crane lives mainly on small animals, what is it in an ecosystem according to Paragraph 2?

3. What's the most important thing in an ecosystem?

4. What may cause an ecosystem to change?

5. What can we do to help protect the ecosystem?