I remember _________ to their party, but I _________ the invitation in the office．
A.being invited; have leftB.inviting; was leavingC.to be invited; have forgottenD.to invite; forget在线课程A
解析：
句意：我记得受到了参加他们的宴会的邀请，但我把邀请书忘在办公室中了。对以前发生过的事情还记得，要用remember doing；把某物忘在某处，要用leave。