几道语法题，请nn们援手

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

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

B.Nearly 99 percent of five hundred million different species of living creatures that appeared  on Earth have  vanished.

C.Vanished are nearly 99 percent of the five hundred million different species of living creatures that appeared on Earth.

D.Of five hundred million different species of living creatures that have appeared on Earth,nearly 99 percent of them have vanished.

E.Of  the five hundred million different species of living creatures that have appeared on Earth,nearly 99 percent of them have vanished.

2.Reseachers hypothesize that granitic soil is the ideal construction materal for the desert tortoise beacause it is not so hard that it makes burrowing or so soft that it could cause tunnels to collapse.

A. so hard that it makes burrowing diffult or so soft that it could cause

B.hard enough to make burrowing difficult or soft enough as to cause

C.so hard as to make burrowing difficult or soft enough so it causes

D.as hard as to make burrowing difficult or as soft as to cause

E.too hard,making burrowing difficult,nor too soft,so as to cause

1 B

2 E

对不对？

答案：1b,2d

两道题以前有网友也贴过。

1. 老版本的E ，percent 后是没有of them的，当时B和E争论很厉害，我当时是有点倾向E，不过现在看看还是简单些的好。

B和E有三个差别：

a. 99 percent 的后置，不知道ETS怎么看，平时这种形式也是比较常见的。

b. E比B在five前多了the，当时有人觉得因为有that，所以应该加这个the。我现在想想也许少了更好，five hundred million 应该是指全部的，加了the也许还暗指还有其它。

c. appeared和have appeared的区别，我原先赞同的观点因为后面出现了have vanished，所以前面也要have appeared来呼应，现在感觉也不一定非要这样对应。

2. 以前给的答案倒是A。好像说D的问题是前一个as应该改成so。我自己现在也说不清楚，也许A中could是不能轻易省的。

不知楼主答案来源的可靠性如何？