Five hundred million different species of living creatures have appeared on Earth, nearly 99 percent of them vanishing.

1. Five hundred million different species of living creatures have appeared on Earth, nearly 99 percent of them vanishing.
2. Nearly 99 percent of five hundred million different species of living creatures that appeared on Earth have vanished.
3. Vanished are nearly 99 percent of the five hundred million different species of living creatures that appeared on Earth.
4. Of five hundred million different species of living creatures that have appeared on Earth, nearly 99 percent of them have vanished.
5. Of the five hundred million different species of living creatures that have appeared on Earth, nearly 99 percent have vanished.

The answer is E. But, what wrong with B. I feel it is more concise.

B时态问题．five hundred million different species of living creatures 用过去时，现在不存在了吗？而

且和have vanished现在不符．逻辑上，结构上都不对．肯定是用现在完成时．

選B的話，B 當中的 that 指涉對象不清，可以是Nearly 99 percent 的生物，也可以是

指 five hundred million different species of living creatures ，會產生語意的歧義，所以 B 不佳。

应该选B,E改变句意了.

意思是在曾经生活过的的那500 billion creatures中.而总数也许不止.
应该选B,E改变句意了.

意思是在曾经生活过的的那500 billion creatures中.而总数也许不止.