单项选择题
Don't（）on the past --- try to be more positive.
A.think B.startle C.dwell D.live
单项选择题 Private employment agencies may not have your best interest（）heart.
单项选择题 He has been（）from the swimming race because he did not win any of the practice races.
单项选择题 We（）to deliver the goods within a week.
