答案C 解题分析 北京经济更发达，人才集聚能力更强。

44.「地理一选修6：环境保护(10分) 为治理水土流失，减少黄河含沙量，长期以来黄河流域实 施人工退耕还林、还草，但可能带来植被退化和水资源失衡等 问题。因此，专家建议未来黄土高原植被恢复不宜继续人工扩 大退耕还林、还草面积，而应以植被自然演替为主。 专家建议未来黄土高原植被恢复应以植被自然演替为主， 试分析其原因。

58.A每次我把一块拼图放在正确的位置，我在精神上就会被这 小小的成功奖励，有动力继续努力。 59.C 60.B 全神贯注拼图让我得到那么多的快乐是令人惊讶和意外 的。

54.A.enjoy B.guess C.remember D.emphasize 55.A.basket B.poster C.picture D,board 56.A.touch B.remove C.draw D.compare 57.A.danger B.boredom C.excitement D.amazement 58.A.mentally B.physically C.strangely D.passively 59.A.grateful B.anxious C.motivated D.shamed 60.A.trouble B.joy C.responsibility D.praise

patience.Then I realized that I learned much more than that.When I 51 1,000 pieces of a puzzle on the table,I 52 not buying a simpler one.I suddenly realized how 53 I was and I couldn't even focus on such a simple task. I decided to solve a puzzle and 54 one simple task like a little child.When I started to look for different pieces to see if they could fit in a larger 55 I started to look for shortcuts. I tried to collect puzzles with similar patterns or colors and 56 their edges. During this time,I slowly forgot all the madness and 57 of quarantine life.Every time I got one piece in the right place,I was 58 awarded by such a small success and 59 to keep on trying.It was surprising and unexpected for me to receive so much 60 from focusing on solving puzzles.

you become more productive. A.Give up a list B.As you finish them C.Do the hardest thing first D.When you have a big task to do E.If you apply the following steps F.And prepare any needed material in advance G.For example,write for 30 minutes every day

【答案与解析】 研究者在全球六个珊瑚礁系统中发现，由于鱼类挑食，大型鱼 类对食物网影响很大。 32.A根据第2段最后一句可知，珊瑚礁的大部分鱼类对食物很 挑剔。 33.B根据第3段中的第2、3句可以推断出，大型鱼类的减少会 影响其他物种的数量 34.D根据第5段第2句可知，六个珊瑚礁的食物网结构大体相 同。 35.D文章开头提出珊瑚礁的食物网比以前认为的更脆弱，接下 来分析了产生这种现象的原因。

B.The 10:15 plane. C.The 8:15 plane. 听第7段材料，回答第8、9题。 8.What does the man want to reserve? A.A single room. B.A double room. C.A business suite. 9.How much will the man pay? A.$160. B.$180. C.$200. 听第8段材料，回答第10至12题。 10.What did Ronak use to do?

Coral reefs are some of the most diverse ecosystems on Earth.In the largest and most complete study of its kind,re- searchers from France and The University of Texas at austin concluded that coral reef food webs are more delicate than previ- ously thought. Researchers made the conclusion after synthesizing ( the stomach contents of most fish species found on six coral reef systems around the world.The team found that the vast majority of reef fish species are very picky about what they eat,rather than feeding on anything they could find. Many conditions can cause the local loss of fish species,such as climate change,commercial fishing and pollution.Such fish

28.What does the 2014 study focus on? A.How a runner is well challenged. B.When a runner is fully prepared. C.How a runner becomes confident. D.When a runner gets injured. 29.What tends to happen to depressed patients about running? A.They have trouble starting to run. B.They don't benefit from running. C.They run without proper equipment. D.They run on their own. 30.What can we infer from the last paragraph about running? A.Running is hard. B.Running is easy to do.