I'm sorry that I happened _____ when you came to see me last nightA:be outB:outC:to outD;to be out

I'm sorry that I happened _____ when you came to see me last nightA:be outB:outC:to outD;to be out
I'm sorry that I happened _____ when you came to see me last night
A:be out
B:out
C:to out
D;to be out

I'm sorry that I happened _____ when you came to see me last nightA:be outB:outC:to outD;to be out
D.
happen to +原形
碰巧

D

D.

d因为happen to do something