1. I've heard so much about you.
久仰！
2. You've had a long day./ You've had a long flight.
辛苦了！
3. Distinguished/Honorable/Respected friends
尊敬的朋友们！
4. On behalf of the Beijing Municipal government, I wish to extend our warm welcome to the friends who have come to visit Beijing.

我代表北京市政府欢迎各位朋友访问北京。
5. On behalf of the Beijing Municipal government, I wish to express our heartfelt thanks to you for your gracious assistance.
我谨代表北京市政府表示衷心的感谢您的大力协助。
6. How are you making out in Beijing?
在北京过得怎么样？
7. I'll surely remember you and your invitation to him.
我一定向他转达您的问候和邀请。
8. American businessmen are welcome to make investment in Beijing.
欢迎美商来北京投资。
9. Your valuable advice is most welcome.
欢迎多提宝贵意见。
10. It's a rewarding trip!
不虚此行!