n.广播完毕的信号;
例句:
I'd better sign off now. Love John.
我得就此停笔. 爱你的约翰.
I've written too much and had better sign off.
我已写得太多,还是就此结束吧.
I would be grateful if you can sign off today.
如果你今天你能够批准,我将感激.