I am sorry to trouble you._____ where can I post my letter?A.but B .and C.so D.if

问题描述:

I am sorry to trouble you._____ where can I post my letter?A.but B .and C.so D.if
说明原因

But
这里表示语气的转折
不好意思麻烦你了,但是我应该在哪里寄信呢?