来自何光的问题
heisonlystudent_____canworkoutthedifficultprobleminmathsA/BwhomCwhichDthat为什么?
heisonlystudent_____canworkoutthedifficultprobleminmaths
A/BwhomCwhichDthat
为什么?


heisonlystudent_____canworkoutthedifficultprobleminmathsA/BwhomCwhichDthat为什么?
heisonlystudent_____canworkoutthedifficultprobleminmaths
A/BwhomCwhichDthat
为什么?
D
他是唯一一个能解出这道数学题的学生.
这是一个定语从句.从句中缺少主语,首先排除A,因为在从句中做主语的关系词不能被省略,再排除B,因为这是宾格,不能做主语,因为先行词student是人,不能用which,which只能指代物.that既能指人,也能指物.