问一道题牛人请进

芹菜宝宝

Paragraph 3: The body that impacted Earth at the end of the Cretaceous period was a meteorite with a mass of more than a trillion tons and a diameter of at least 10 kilometers. Scientists first identified this impact in 1980 from the worldwide layer of sediment deposited from the dust cloud that enveloped the planet after the impact. This sediment layer is enriched in the rare metal iridium and other elements that are relatively abundant in a meteorite but very rare in the crust of Earth. Even diluted by the terrestrial material excavated from the crater, this component of meteorites is easily identified. By 1990 geologists had located the impact site itself in the Yucat region of Mexico. The crater, now deeply buried in sediment, was originally about 200 kilometers in diameter.

3. Which of the following can be inferred from paragraph 3 about the location of the meteorite impact in Mexico?

○ The location of the impact site in Mexico was kept secret by geologists from 1980 to 1990.

○It was a well-known fact that the impact had occurred in the Yucat region.

○Geologists knew that there had been an impact before they knew where it had occurred.

○The Yucat region was chosen by geologists as the most probable impact site because of its climate.

为何选C??????不是A

zxm1988

Scientists first identified this impact in 1980

By 1990 geologists had located the impact site

这两句不就说明C没错嘛

至于A，你从哪里看出来site was kept secret

joycelee1022

A项里面was kept secret by geologists from 1980 to 1990没有原文可以印证的吧

fujuoo

Scientists identified the impact rather than location in 1980. And the location was not identified until 1990. So the knowing of impact is previous the knowing of location. This is what the choice C expresses.

For choice A, scientists do not know the location until 1990, so there is no secret kept about location before that time.