Leaving the doors unlocked is an open invitation to burglars.

　　出門不上鎖無異于開門揖盜。

　　She had wangled an invitation to the opening night.

　　她弄到了一張首映之夜的請柬。

　　Admission is by invitation only.

　　憑請柬入場。

　　I accepted the invitation thankfully.

　　我愉快地接受了邀請。

　　She graciously accepted our invitation.

　　她落落大方地接受了我們的邀請。