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
答案是A. 不是很理解这里定语句子的结构, 应该是plant and animal species are known....请帮忙解释一下。谢谢! |