根据中文提示，从下面所给的七个选择项中选出五个最佳选项补全对话。所选选项必须符合 对话语境与英语表达习惯。
提示：加拿大商人Alex来中国访问，在北京首都国际机场办理入境手续时与海关官员(Officer) 进行简短对话。
(Alex=A; Officer=O)
O:Good morning.
A: ___51___
O:Your passport, please.___52___
A:I am from Canada.
O: ___53___
A:I am here for business.
O: ___54___
A:About two weeks.
O:OK. Take your passport and have a nice trip.
A: ___55___

A.Thank you.
B.Here you are.
C.Good morning.
D.Where are you from?
E.How's everything with you?
F.Why do you come to China?
G.How long will you stay in China?