_______ child as she is, she find in _______surprise that sh

这是用于as引导的让步状语从句中部分倒装中的形容词或名词置于句首的句式.
eg.
形容词置于句首的:
Proud as the nobles are (＝Although the nobles are
proud), they are afraid to see me．
名词置于句首:
Child as he is (＝Although he is a child), he knows a lot.
但在你说的这个句子名词前面有个不定冠词,但却没有形容词,注意哦,只有在名词前有形容词修饰时,as 引导的倒装句中才需要要保留不定冠词.
eg.
A bad-tempered man as he is (＝Although he is a
bad-tempered man), he loves me deeply．
in surprise 是固定用语,惊奇地,相当于副词
祝学习进步

这是as引导的让步状语从句，as she is child,虽然他是小孩子。

(adj)+n+as+sb+be 这个是固定搭配，名词前不加冠词
In surprise 表示一种状态，惊讶的状态，状态这个肯定不加冠词...

as 引导的让步状语从句， 名词提前不用冠词， in surprise 是个固定短语， 意思是惊讶地
所以这道题正解为C