half of the class( )most of the work.some of the work( )really difficult.a.has done; are b.has don

题目

half of the class( )most of the work.some of the work( )really difficult.a.has done; are b.has don
选什么?为什么?
family和class什么 时候谓语是单数呢？什么时候用复数？

答案

Half of the class (have done) most of the work.Some of the work (is) really difficult.这里class是一个集合名词,比如这个班上有五十人,那么这里就是指25 people,因此谓语是复数的work为不可数名词,some of the ...