1 . 阅读下面短文，根据短文内容填空。在未给提示词的空白处仅填写1个适当的单词，在给出提示词的空白处用括号内所给词的正确形式填空。

A series of water-conserving and recycling designs have been put into place     1     (improve) water usage for snow making, human consumption and other purposes, according to the Beijing 2022 organizing committee.

Around 90% of the snow     2     (use) at the Alpine skiing venue for the Pyeongchang 2018 Winter Olympics was reported artificial, while artificial snow     3     (be) also a feature of Vancouver 2010 and Sochi 2014.

2 . In January 1958, Rachel Carson received a letter from her fiend Olga Owens Huckins. Huckins lived in an area of Massachusetts where the state was trying to get rid of mosquitoes. They had used planes to spray a mixture of fuel oil and DDT (a pesticide, which can kill pests such as insects, weeds and rodents) all over the area around Huckins home. DDT was supposedly harmless but the morning after the spraying. Huckins found several of her favorite birds dead outside her house. And the spraying did not even kill all of the mosquitoes, in fact that summer there were more of them than ever before. Huckins asked Carson if she knew someone in Washington that could help prevent future spraying.

Carson had been hearing about DDT since a Swiss chemist discovered it could be used to kill insects in 1939. To many people, DDT seemed like a miracle substance. Farmers were excited about saving their crops from pests. Doctors and others were excited about saving people's lives by killing disease-carrying insects. But to Carson. DDT appeared to be dangerous to all living creatures.

The more Carson found out about DDT and other pesticides, the more she realized that she needed to help stop future spraying. Carson decided to write a book about pesticides. She said, “There would be no future peace for me if I kept silent.” She called her book Silent Spring.

Carson had spent her life studying, observing, and writing about nature. She was a trained biologist and a talented writer who knew how to present scientific information in compelling stories. Before Silent Spring, she had written other books from the perspective of fish birds, islands and oceans. Carson knew that all things in nature exist in a delicately balanced ecosystem. In Silent Spring, Carson wrote that. although the ecosystem can adjust to changes, it needs time. Carson believed that people u the 1950s were using pesticides carelessly Nature didn’t have time to adjust, wrote Carson, because so any pesticides had been used in such large quantities in such short tame.

1. Why did Huckins write a letter to Rachel Carson?

A．To tell her some bad news.	B．To turn to her for help.
C．To advise her to write a book.	D．To ask her some questions.

2. Which of the effects the spraying of the mixture in Massachusetts had is right?

A．It killed pests such as insects, weeds and rodents around Huckins' home.

B．It killed all of the mosquitoes.

C．There were more birds than ever before

D．It had bad effects on ecosystem.

3. Who would not be happy with DDT?

A．Gardeners.

B．Farmers.

C．Doctors.

D．Biologists.

4. What's the best title of the passage?

A．Rachel Carson's research on nature	B．Rachel Carson's life
C．Rachel Carson's Silent Spring	D．DDT's bad effects on ecosystem