The students are hard-working and ready to help others should be praised.
A. who
B. whom
C. which
D. whose
网友回答
(答案→)A. who
B. whom
C. which
D. whose
解析：考查定语从句。本题定语从句的先行词是the students，后面的定语从句中缺少的是主语，因为先行词是指人的名词，故使用who指代先行词在句中做主语。句意：那些奴隶学习且乐意帮助别人的学生应该得到表扬。故A正确。