邀請函的英文：
invitation
參考例句：
Entry to this competition is by invitation only.
此次競賽的參賽只憑邀請函。Nobody in the office had received an invitation to the party.
在辦公室裏沒有人收到邀請函去參加這個宴會。invitation是什麼意思：
n. 邀請；請柬；引誘
Whomever you invite will be welcome.
你邀請的.任何人都將受歡迎。
He was upset at not being invited.
人家沒邀請他，他很不痛快。
A Bad padlock invites a picklock.
壞鎖招人撬。
Entry to this competition is by invitation only.
此次競賽的參賽只憑邀請函。
She was favored with an invitation.
她受到了邀請。