下来选项中，不属于城市生态系统特点的是
A．城市是人为的生态系统
B．城市生态系统是脆弱的
C．城市生态系统是独立的
D．城市生态系统中消费者多，生产者少
答案：C
题目分析：城市生态系统是城市居民与其环境相互作用而形成的统一整体，也是人类对自然环境的适应、加工、改造而建设起来的特殊的人工生态系统，城市生态系统中人类起重要支配作用，植物种类和数量少，消费者主要是人类，城市生态系统由少量的植物（生产者），人、少量的动物（消费者），分解者以及生活环境组成，需要从外部购进大量的食物，生物圈是一个统一的整体，生物圈中的每一个生态系统都与周围的其他生态系统相互关联，故C符合题意。
| 阅读理解。 |
| Want to be an astronaut? Then "study hard, stay healthy and have perseverance (毅力). This is what Chinese astronaut Fei Junlong and Nie Haisheng said in a talk with some students. Students were interested in the astronauts' space lives. They asked questions like "Did you see the Great Wall from space?" Fei and Nie said they didn't see the Great Wall. But they felt excited when they passed over China, including Taiwan, the island "looked very beautiful, like a jade (翡翠). Speaking of their lives beyond the earth, the two astronauts said cooperation (合作) with each other was most important, "we are like the left and right hands," they said. Young people wanted to know how the astronauts developed their careers. "How did you decide to be astronauts when China's space industry is still beginning?" asked a young woman. The astronauts said it was because of their love of flight and also the need of the country. They said their love of flight could be seen from their children's names. Nie's daughter is called "Nie Tianxiang" which means "flying up high". Fei's son is called "Fei Di", which sounds like "feidie", meaning UFO. After the success of Shenzhou VI, China plans to put a man on the moon and build a space station in 10-15 years. |
| 1. If you want to be an astronaut, what should you do from now on? |
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| A. We should be interested in the astronauts'space life. B. We should change our names. C. We should study hard, stay healthy and have perseverance. D. We should love the flight and our country |
| 2. When astronauts work in space, they must ________with each other. |
[ ] |
| A.shake hands B.cooperate C.stay D.talk |
| 3. In 10-15 years, China could put a man on _______ and build a space station. |
[ ] |
| A.UFO B.Shenzhou VIII C.the sun D.the moon |
| 4. Which of the following is true? |
[ ] |
| A. FeiJunlong met UFO in space B. Nie Haisheng saw the Great Wall from space. C. Fei and Nie make a contribution to China's space industry. D. The astronauts couldn't see Taiwan from space. |
| 5. Nie and Fei want to be astronauts because of ____________ |
[ ] |
| A.their love of flight B.the need of the country C.their daughters D.both A and B |