I'm _______(ture) sorry that I've kept you waiting so long

I'm _______(ture) sorry that I've kept you waiting so long
I'm _______(ture) sorry that I've kept you waiting so long

I'm _______(ture) sorry that I've kept you waiting so long
truly

truly 修饰形容词sorry 用副词

truly
用副词修饰形容词sorry，表示一种程度，相当于very。
让你等了那么久我感到非常抱歉。

truly修饰sorry

truly
sorry 是形容词，修是形容词用副词