PREP07-83 求救求救！！

刘小谁

83. (28949-!-item-!-188;#058&004110)

The number of plant and animal species that humans are known to have forced to extinction in the

last half millennium is over 800.

(A) humans are known to have forced to extinction

(B) humans are known as having forced to become extinct

(C) humans are known for forcing to become extinct

(D) are known that humans forced to become extinct

(E) are known as having been forced to extinction by humans

答案选A，解释说be know to do 是正确的习语...但是这句话是什么意思，习语是什么意思，丝毫看不懂啊...求指教啊...

kerrzang

在过去的五百年间，已经所知因人类而灭绝的动植物种类数量超过了800.  
另外，be know to do 应该是“为...所知做了什么” 比如：Tom is know to make Larry heart broken. 为人所知的，Tom让Larry伤心了。

刘小谁

在过去的五百年间，已经所知因人类而灭绝的动植物种类数量超过了800.  
另外，be know to do 应该是“为...所知做了什么” 比如：Tom is know to make Larry heart broken. 为人所知的，Tom让Larry伤心了。

-- by 会员 kerrzang (2012/3/19 11:28:06)

瞬间清晰了!!跪谢跪谢~！！！