Unit 22 基础练习题 2021-2022学年北师大版高中英语选修八

Unit 22 I. 根据所给提示，用本单元所学词汇完成下面短文（每空一词）。 This year must be a 1. r________ year for both humans and animals. Hundreds of thousands of people have lost their lives to coronavirus, and in the animal world full-blown extinction continues to affect various species. The World Wildlife Fund (WWF) has warned that animal populations have declined by an average of almost 70% in less than 50 years. Climate change, human actions, 2. h________ loss and other factors have combined to leave many animals facing a hopeless future — and some facing none at all. The river dolphin is one of them. River dolphins are flagships for the health of the world's great rivers. However, they are extremely vulnerable (脆 弱 的 ) to the huge changes we are making to their environment. Despite major 3. c________ efforts and signs of progress, all the world's river dolphin species are now threatened with extinction. It seems unlikely that they would go extinct next year, but some scientists already consider them “functiona