英语单项选择题(which is the best?Tell me why?)

英语单项选择题(which is the best?Tell me why?)
1 My good friend Jane will go back to her country tomorrow.I'm going to __ at the airport.A send off her B send her off C see off her D see her off(send off 跟see off ）
2 My father has ___ in the hospital for quite a few years.A worked B gone C come D left
3 May I ask where the Greens are?
---Well,they ___England.They have been there for nearly five days.
A are gong to B will go to C have been to D have gone to