关于动名词,his parents insist on

问题描述:

关于动名词,his parents insist on
his parents insist on _____ to college
a.he should go
b.he go
c.his going
d,him to go
我知道insist on doing 但不知道为什么加his

insist on doing sth 指的是his parents坚持 去上大学.加上his 指的是他父母坚持他应该去上大学.
明白了吗?