2. 外语
  3. The Earth has been stripped of up to 90% of its species five times before in the past 450 million years. Now it’s about to happe

The Earth has been stripped of up to 90% of its species five times before in the past 450 million years. Now it’s about to happe

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问题     The Earth has been stripped of up to 90% of its species five times before in the past 450 million years. Now it’s about to happen again—and this time there’s no rogue asteroid(小行星)to blame. One of the first great rules of terrestrial biology is that no species is forever. The Earth has gone through five major extinction events before. The result of all of the extinctions was the same: death, a lot of it.
    As increasingly accepted theories have argued—and as the Science papers show— we are now in the midst of the sixth great extinction, the unsettlingly-named Anthropocene(人类纪), or the age of the humans.
    As the authors of all this loss, we are doing our nasty work in a lot of ways. Overexploitation—which is to say killing animals for food, clothing or the sheer perverse pleasure of it—plays a big role. So we get elephants slaughtered for their tusks, rhinos poached(偷猎)for their horns and tigers shot and skinned for their pelts, until oops— no more elephants, rhinos or tigers.
    Habitat destruction is another big driver, particularly in rainforests. And you don’ t even have to chop or burn an ecosystem completely away to threaten its species; sometimes all it takes is cutting a few roads across it or building a few farms or homes in the wrong spots.
    Then too there is global warming, which makes once-hospitable habitats too hot or dry or stormy for species adapted to different conditions. Finally, as TIME’s Bryan Walsh wrote in last week’ s cover story, there are invasive species—pests like the giant African snail, the lionfish—which hitch a ride into a new ecosystem on ships or packing material, or are brought in as pets, and then reproduce wildly, crowding out native species.
    It oughtn’ t to take appealing to our self-interest to get us to quit making such a mess of what we ’re increasingly coming to learn is an exceedingly destructible world. But it’ s that very self-interest that led us to make that mess in the first place. We can either start to change our ways, or we can keep going the way we are—at least until the Anthropocene extinction claims one final species: our own.
The sentence "this time there’ s no rogue asteroid(小行星)to blame" means______.
选项 A、people blamed asteroids because they are too naughty
B、people feel pity about not having an asteroid to blame
C、the earth will experienced another extinction because of the asteroids
D、the asteroids once served as the reason of the past extinction
答案D
解析 词汇题。文章前面一直在说之前的五次物种大灭绝，后面要引出的是这一次的物种消亡。提到了“it’s about to happen again”和“this time”，可见之前的灭亡原因是小行星。故选D。A、B都是字面意思，而C则意思相反。
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