a group of 的用法.
问题描述：
a group of 的用法.
a group of students is/are playing happily.
there is /are a gruop of students running on the grond.
单数还是复数.is 还是are
答
a group of接可数名词.A group of visitors are visiting Summer Place.
一群游客正在参观颐和园
第二个,一群学生在操场上跑步,强调的是一群所以用单数.