单项选择题
It was（）computer games that cost the young man a lot of precious time that he should（）on his lessons．
A.to play；be spendingB.playing；spendC.played；have spentD.playing；have spent
单项选择题 —What do you think of the CD？—（）.
单项选择题 I can’t take part in the party tonight because I have to（）my little sister.
单项选择题 You know （）about it than Tom does．
