21. --- Betty , welcome to my birthday party . Please make yourself at home .
--- ________.
A. The same to you B. No , not really C. Thank you D. Here you are
22. The man fled aboard, trying to avoid ________.
A. catching B. being caught C. to catch D. to be caught
23.The problem is _______ we can arrive there before 6:00 tomorrow morning.
A. which B．whether C．when D．that
24.It is ________ that people will not agree with what the manager at the meeting.
A. certainly B. sure C . certain D. surely
