题目内容：

A strong EI Nino（厄尔尼诺暖流）causes the temperature around the world to rise. “That’s how we will see the influences of climate (气候) change", says Michael Mann, a climate scientist at Penn State University.

The Great Barrier Reef (礁) is far beyond its name. Coral (珊瑚) of all shapes, sizes and colors covers more than 130,000 square meters off the coast of Australia, making it the world's largest reef system with many amazing kinds of life under the sea.

But today the Great Barrier Reef is dying. The waters around the reef become warmer. That warming then causes the bleaching(白化).The bleaching takes the color and the life out of the coral. Bleaching happens when the warm water and pollution drive away the living things that live on the coral and give it color. Within weeks, the reef could die, leaving behind a forest of lifeless, bone white coral. Scientists believe the bleaching may kill more than 15% of the world’s coral. The Great Barrier Reef isn't alone. This is the longest bleaching event ever recorded, " says David Kline, a scientist.

But a bigger worry may be what the bleaching suggests about future climate(气候)change. Climate change may be slow sometimes, but other times it takes great leaps forward, "says Steve Palumbi, an ocean scientist at Stanford University.

Local solutions like reducing fishing and cleaning up, pollution can help slow reef loss, but scientists say a global(8)problem requires a global solution. Nearly 200 countries agreed last year to work to keep global temperatures from rising more than 3. 6F by 2100, but that goal will be hard to reach.

1.The underlined word “It” in Paragraph 2 refers to (指代)_____________.

A. the country –Australia B. the coast of Australia

C. the coral under the sea D. The Great Barrier Reef.

2.What does the writer mean by saying "The Great Barrier Reef isn’t alone. "?

A. There are many other reefs beside the Great Barrier Reef.

B. There are kinds of living things on the Great Barrier Reef.

C. The Great Barrier Reef is becoming warmer and warmer.

D. Some other reefs have the same problem as the Great Barrier Reef.

3.After reading the article, you can learn that__________.

A. the climate is changing quickly within a short time

B. it's hard to see colorful coral when bleaching happens

C. the global warming is the only reason for the death of reefs

D. lots of countries found it easy to make the temperature low

4.What's the writer’s main purpose in writing the article?

A. To draw more attention to global warming B. To explain how bleaching happens.

C. To advise Australians to solve global warming. D. To explain why the world gets warm