Question

选择题（ ){How/What}smart the boy is! Indeed.He proved（）｛he/he will be/himself/him was}

clever by working out the difficult question.

Answer 1

【How】smart the boy is! Indeed.He proved 【himself】 clever by working out the difficult question.
那个男孩多灵力啊。他通过解决那个困难的问题，证明自己很聪明。

第一个空，关于形容词，用how，如果是关于名词，用what。这里是感叹smart
第二空，he 的宾格，himself

Answer 2

How smart the boy is! He proved himself clever by working out the problem.
How + adj +主语+动词！