I've been told that in English study__idioms is of great importance

问题描述:

I've been told that in English study__idioms is of great importance
A.programmar as well as
B.not only grammar but also
为什么选A,B不是也有就近的用法么?

B的确有就近用法,可是句子重心是but also后面的成分,由题得but also 后面是复数,故谓语动词应用复数.题中的谓语动词是is,是单数.这就矛盾了,所以B是错的.