21 －We had_____ really cold February this year
－I can’t remember______ spring when it snowed in Changzhou .
A. a;不填 B. 不填;the C. the; a D. a; a
22. _Did you remember to give Mary the money you owed to her?
_Yes, I gave it to her ____ I saw her.
A while B the moment C suddenly D once
