主谓一致问题1.a mass of +名词作主语谓语动词用单数还是复数?2.masses of+名词作主语谓语动词用单数

a mass of +名词作主语时,谓语
动词的单复数情况取决于of后的名词是单数还是复数,或者是具体的上下文而定.
masses of+可数名词或不可数名词"作主语时,谓语动词应与名词的数保持一致.
如:例题:)~
Whom did you_______the packet at the post office
—Jack.There_______masses of work for him to do,but he managed to finish the work as required.
A.have fetched;was B.have fetch;were
C.have to fetch;were D.have fetch;was
解题思路:第一个空格考查"have sb…do sth."结构和陈述句变成特殊疑问句的用法;"masses of+可数名词或不可数名词"作主语时,谓语动词应与名词的数保持一致.
答案:D

单数，复数都可以。