611.We should be careful in our studies.This is _______ everyone as carelessness causes mistakes.

A.because of

B.true of

C.up to

D.related to

612.The time he has devoted in the past years ______ the disable is now considered _____ of great value.

A.to help;being

B.to helping;to be

C.to help;to be

D.helping;being

611.答案是B;

be true of…适用于。

612.答案是B;

devote one’s time to doing sth.,而consider sth.to be of great value认为…很有价值。