Biosphere Ⅱ was a spectacular failure.
The gleaming glass-and-concrete habitat sprawling across the desert in Oracle,
Arizona, was supposed to support eight human "biospherians" for two years. But
the seal has to he broken before the experiment ended in 1993. Oxygen had fallen
to levels normally seen at an elevation of 17,500 feet. Nitrous oxide had risen
to the point where it threatened to cause brain damage. The fresh water supply
became contaminated, and vines smothered (厚厚地覆盖) food plants. Insect pollinators
(传授花粉的生物) and many other species became extinct. By the end, Biosphere Ⅱ was
overrun with swarms of ants and cockroaches. Scientists who
gathered recently to review the Biosphere Ⅱ experiment reached a disturbing
conclusion: "No one yet knows how to engineer systems that provide humans with
the life-supporting services that natural ecosystems produce for
free." The problem is that these ecosystems are undergoing
wrenching changes. Water and air quality, while improving in some regions, are
deteriorating in many others. Carbon dioxide levels in the atmosphere arc
climbing. The world's population could reach 10 billion by 2050. And famed
Harvard biologist Edward O. Wilson says the current rate of species losses puts
us "in the midst of one of the great extinction spasms (突然进发) of geological
history." All of which makes many ecologists wonder whether humans too will soon
become extinct. It's an incredibly important but incredibly difficult question.
If we continue on this course, we're heading for a world in which we will have
to engineer services we've always received for free from nature. That's why the
failure of Biosphere Ⅱ was so disturbing: it proves that we don't yet know how
to do that. The Biosphere Ⅱ experience demonstrated that
maintaining human life is a tricky proposition-especially if we can no longer
rely on the services provided by natural ecosystems. If we are currently living
through a mass extinction, as Wilson believes, we should consider the past. In
the great Permian extinction 245 million years ago, 96 percent of species
perished. Eventually, the Earth was repopulated with a rich collection of new
species, but it took 100 million years. "That should give pause to anyone who
believes that what Homo sapiens (现代人) destroys, nature will redeem," Wilson
says. "Maybe so, but not within any length of time that has meaning for
contemporary humanity."
单选题
The seal of the Biosphere Ⅱ had to he broken before the experiment
ended because ______.
A. the had climate of the desert made the human biospherians ill
B. the poisonous air caused brain damage of the human biospherians
C. the ecosystems in it became so bad that the human biospherians can't
live
D. the human biospherians were defeated by swarms of ants and
cockroaches
【正确答案】
C
【答案解析】[解析] 文中第一段“has to be broken before the experiment ended. Oxygen had fallen to levels normally seen at an elevation...cockroaches”中可以看出氧气浓度下降、氧化亚氮含量超高、水资源污染、许多昆虫及其他物种绝迹是人类无法生存其中、生态圈提前开启的重要原因。文中C选项表达的亦为此意。
单选题
What is the purpose of the experiment mentioned in this passage?
A. To propose measures to hold back environmental deteriorating.
B. To predict environmental deteriorating that can cause vast
destruction.
C. To limit the destruction that environmental deteriorating may
cause.
D. To see if humans can engineer systems providing life-supporting
services.
【正确答案】
D
【答案解析】[解析] 第二段“No one yet knows how to engineer systems that provide humans' with the fife supporting services that...”中可以看出科学家做试验的目的是想知道“how to”创造出“life-supporting services”与选项D意思一致。
单选题
It is implied that many ecologists ______.
A. believe the world's ecosystems are in an undesirable condition
B. agree that the environment of the world is not as bad as it is thought to
be
C. appear somewhat unconcerned about the state of the world's
environment
D. have thorough and comprehensive knowledge of the world's
environment
单选题
Edward O. Wilson believes that the mass extinction happened in the past
______.
A. is good news for humans
B. is bad news for humans
C. promoted the development of humans
D. blocked the development of humans
【正确答案】
B
【答案解析】[解析] 文中最后一句“That should give pause to anyone who believes that what Homo sapiens destroys, nature will redeem,”“...not within any length of time that has meaning for contemporary humanity”中可以看出大量物种的灭绝将对人类造成极大的危害，所以它对人类是个坏消息。故B选项正确。
单选题
The message the author wishes to convey in the passage is that ______.
A. humans will become extinct if continuing to destroy the nature
B. man has to limit his activities to slow down environmental
pollution
C. human will continue to develop in spite of the changes of nature
D. maintaining human life is a tough question but still can be
solved