21. --I’m afraid I’ll come back in an hour.
-- There is no need to rush back. Just _________ .
A. take it easy B. take your time C. help yourself D. feel at home
22. --What can I do for you?
-- I’d like to buy a present for my son, _______ at a proper price but of great use.
A. one B. the one C. which D. that
