v.退訂；取消訂閱
If you would liketo opt out of receiving email, you may unsubscribe at any time. 如果您決定不接受此類(lèi)郵件，可在任何時(shí)候退訂。
End users are able to subscribe and unsubscribe to the published alerts made available to them. 終端用戶(hù)能夠訂閱他們可獲得的發(fā)布警示信息，并可取消訂閱。
