insist on sth.
doing sth.这里的ing形式可以理解成是动名词形式,也就是有名词的性质,doing sth.可以理解成是sth.如 I like reading.可以理解动名词reading是“读书”,这么一件事情,我喜欢“读书”这事儿.
sb's doing sth.某人的某行为,也可以把动名词理解成是名词性质
I like his helping the others.我喜欢他乐于助人这种行为.
这题目同理,insisit on something
insisit on doing sth.-----insist on accepting something
insist on sb's doing sth------insist on his accepting something