(单选题)

, there are still some studying problems that, when in time, can become more complicated later on.

A.As he is an intelligent boy; not solved

B.An intelligent boy as he is; not to be solved

C.Intelligent boy as he is; not solved

D.As he is an intelligent boy; not being solved

参考答案：C

参考解析：

考查as引导的让步状语从句和when引导的时间状语从句。句意：尽管他是一个聪明的孩子，但仍有一些学习上的问题，如果不能及时解决，以后可能会变得更加复杂。as引导的让步状语从句，as放在句首时，句子必须倒装，表语提前且倒装后表语前面的冠词要省略。that can become more complicated later on是一个完整的定语从句；when not solved in time是时间状语从句，作为插入语隔开了定语从句that与其后面的成分。而且when not solved in time的主语是some studying problems，而且含有be动词are，所以可以省略主语和be动词，故选C。

知识点：

______, there are still some studying problems that, when ______ in time, can become more complicated later on.

, there are still some studying problems that, when in time, can become more complicated later on.