问答题 Listen to the following passage. Altogether the passage will be read to you four times. During the first reading, which will be done at normal speed, listen and try to understand the meaning. For the second and third readings, the passage will be read sentence by sentence, or phrase by phrase, with intervals of 15 seconds. The last reading will be done at normal speed again and during this time you should check your work. You will then be given 1 minute to check through your work once more.

Counting Species

【正确答案】

【答案解析】[听力原文]
It"s generally accepted that many species have yet to be discovered, / but until now nobody has devised a reliable way. / Suggestions for total numbers have ranged from 3 million to 100 million, / but most of these have been no more than intelligent guesses. / Scientists from the Census of Marine Life devised a counting method / by identifying numerical patterns linking data on known species. / They believe that there should be about 8.7 million types of living things, / three quarters of them animals and the rest plants. / The scientists warn that human activity is hastening extinction. / Many of the unknown species may disappear before we discover them.

[解析] 本文主题：地球上的物种。本文是一篇科普说明文，有一些大数字，如3 million，100 million，在听写时需注意。文中需要注意的较易拼错的单词有“species，reliable，intelligent，census，marine，numerical”，需要注意时态和单复数的单词有“devised，patterns，quarters，extinction”。