二．单选题（15分）
21. ________ he is good at playing basketball, he failed to join the school basketball team yesterday.
A. Since B. Unless C. Though D. Because
22. Lily _______ eat lots of desserts after supper last year, so she was very fat then.
A. used to B. was used to C. got used to D. had been used to
23. He will never forget the days_________ he spent in Australia last year.
A. when B. which C. on which D. earned
