Question

这句“动名词”我不太懂,怎么去理解?

Answer 1

I must apologize for interrupting you.很抱歉打扰/打断你.

(表示说话者当下就是在打扰/打断的状态下)

I must apologize for having interrupted you .很抱歉打扰/打断你.

(表示说话者是在打扰/打断之后所做的道歉)