I ve heard so much about you.
Long time no see.
You've had a long day. You've had a long flight.
Distinguished/Honorable/Respected friends阁下（多用于称呼大使）Your Excellency我代表北京市政府欢迎各位朋友访问北京。
On behalf of the Beijing Municipal government, I wish to extend our warm welcome to the friends who have come to visit Beijing.
On behalf of the Beijing Municipal government, I wish to express our heartfelt thanks to you for your gracious assistance.
How are you making out in Beijing?
I'll surely remember you and your invitation to him.
American businessmen are welcome to make investment in Beijing.
Your valuable advice is most welcome.
Its a rewarding trip!
As you have a tight schedule, I will not take up more of your time.
Please remember me to Mr.Wang.
Thank you so much for coming.
Hope you'll come again.
Hope you'll visit Beijing more often.
I will see myself out, please.
Have a nice trip!