My sister told me she would intruduce( )idiom to me

问题描述:

My sister told me she would intruduce( )idiom to me
A a B an C the D/

名词前面要加冠词,排除D
A,B是不定冠词,C是定冠词
the用于特指的,或者前文出现过的名词之前
a,an用于第一次出现的名词之前
排除C
idiom是原因音标开头,用an
选B