单选题 These students______the cause of helping those who are not able to help themselves.

A. are content with
B. are sound like
C. are absorbed at
D. are committed to

【正确答案】 D

【答案解析】这句话的意思是说，学生们投入到帮助那些不能自助的人们工作中。(A)be content with满足于……；(B)sound like听起来、似乎，一般不用被动语态；(C)be absorbed in全神贯注于、专心于，后面一段不用介词at;(D)be committed to投身于……贡献于……。