题目内容：

The class which ____(was,were) divided into four groups_____（has,have）not agreed among themselves about where they should go and have a picnic.

优质解答

was此处class作整个班级讲,是单数
have此时class作全班同学讲,是复数
family这个单词也有类似的用法——即可作家庭,也可作家庭成员