A lot of language learning ,has been discovered, is happening in the first year of life, s

A lot of language learning , has been discovered, is happening in the first year of life, so parents should talk much to their children during that period .
A. as
B. it
C. which
D. this

(答案→)A. asB. itC. whichD. this解析：试题分析:句意：正如人们发现的，大量的语言学习是发生在人出生后的第一年，所以家长们应该在这段时期要多和孩子讲话。从结构判断此处是非限制性定语从句，排除B、D选项；as引导定语从句译成“正如，就像　”，而which 译成“这一点，”，所以答案选A。

这个问题我还想问问老师呢