问题 解答题

阅读下列材料,回答有关问题.

在纽约动物园的大型草地上,每年10月份的最后一天都竖起一排墓碑.“濒于灭绝物种公墓”中的每块石碑都是为灭绝的一种物种而立的,每年都有新的墓碑出现.现在,人们普遍认为,物种灭绝的速度远远超过了原来的自然进化过程中消亡的速度.

在刚刚开始的世纪里,物种灭绝可能会比以前增加10倍.到2100年,地球上

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的植物、动物以及其他生物将会消失.

在过去的100年,地球上湿地减少了一半,因此,众多的动物和植物便失去了生存空间.大约20%的淡水鱼类、9%的树种消亡或面临消亡的危险.在海洋中,被捕捞的鱼类超过了自然繁殖的数量,在被捕捞的鱼中,70%的鱼成了食品.

地球上几乎一半的陆地被人为地改变,沼泽地和水潭干涸,森林和草地变成了农田、城市和道路.另外,全球森林面积急剧减少也是生物消亡的最好证明.

(1)进入20世纪后,造成生物消亡的主要原因是什么?

(2)为了有效阻止生物进一步的消亡,我们应采取哪些措施?

答案

(1)由于人类的活动,对环境的改造幅度已经很大且地域扩张也很厉害,导至环境变化太大,很多物种的生活地域越来越小,且不能适应环境改造所带来的新的环境,以至于灭绝,如乱砍滥伐、过度放牧、不合理的开发(围湖造田、垦荒、湿地开发等)、使生存环境被破坏与改变,不再适和生物生存,导致野生生物的濒危或面临灭绝.

(2)保护生物的多样性,我们在遗传物质、物种和生态环境三个层次上制定了保护战略和不同的措施,建立自然保护区是保护生物多样性最为有效的措施;保护生物多样性的根本措施是保护生物的栖息环境和保护生态系统的多样性.

故答案为:(1)人类活动对生物栖息地的破坏.

(2)建立自然保护区;保护生物的栖息环境等.

问答题
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     An American space company says a powerful new rocket should be ready for a test launch by the

end of 2012. The company is Space Exploration Technologies, or SpaceX. Its new rocket is called the

Falcon Heavy.

     Company officials say it'll be able to transport satellites or spacecraft weighing up to 53 metric tons

into orbit. Fiftythree metric tons is 117,000 pounds. That load weight is double the capacity of NASA

space shuttles. The space agency is retiring its shuttles after thirty years.

     Elon Musk is the chief executive officer of SpaceX. He says the Falcon Heavy will be the second

most powerful rocket ever. He says it was designed to carry satellites and other equipment into space.

He says the rocket was designed to meet NASA's ratings for human flight safety. So it could someday

be used to carry astronauts and other travelers into space.

     Mr. Musk says the Falcon Heavy could also be used for missions(任务) like carrying a robotic lander

to collect samples from Mars. He says, "It has so much more capability than any other vehicle that I think we can start to consider missions like a Mars sample return, which requires a tremendous amount of lift

capability because you've got to send a lander to Mars that still has enough propellant(推进物) to return

to Earth."

     The first launch is planned from the company’s launch site at Vandenberg Air Force Base in California. A launch from Cape Canaveral, Florida, is expected in late 2013 or 2014.

     In time, SpaceX hopes to launch ten Falcon Heavy rockets a year. It says the rocket should cut back

on launch costs to about 2,000 dollars a kilogram.

     SpaceX already has a billionandahalfdollar deal with NASA to use a smaller rocket to transport

cargo(货物) to the International Space Station. The rocket is the Falcon 9, and the deal is for after the

two last shuttles-Endeavour and Atlantis-are retired this year.

1. What do we know about the feature of the new rocket from the second paragraph?

(No more than 11 words)

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2. Why did SpaceX want to design the new rocket?(No more than 16 words)

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3. Why can the new rocket be used to carry a robotic lander to collect samples from Mars?

(No more 6 words)

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4. What will SpaceX do for the NASA after Endeavour and Atlantis are retired?

(No more than 14 words)

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