Question

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.                                          (2012·安徽，29)

A．as  B．it

C．which  D．this

Answer

【解析】A

解析 句意为：正如被发现的那样，大量的语言学习是在人生的第一年发生的，所以父母应当在那个时期和孩子多说话。空白处所在句为非限制性定语从句，故B、D两项可排除。由句意知空格处的关系词指代a lot of language learning is happening in the first year of life这个句子。指代某个句子时，as引导的非限制性定语从句可后指或前指，而which引导的从句只能前指。此处为后指，因此A项正确。