Human Extinctions!

[gmat_perfect]

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

[spoiler]OA: A[/spoiler]

[Patrick_GMATFix]

Idiom.

"Known" + to

Humans are known to have done something. Only A gets it right.

-Patrick

[indiantiger]

Dude,

Are you seriously having problem with these questions? Or are you just adding questions to increase your post count. If you are having problem with something specific in the question can you please post it along the question. This way people or instructors ( all of whom are really helpful) can clear your doubt.