I am ashamed, sir, that I wasted the many hours __________ I should have studied in class.
27.If you had worked hard, you ______ so anxious now.
26.______ I'm willing to help, I do not have much time available.
25.The rise of oil prices made scientists search for new energy resources ______ oil.
24.You didn't believe John won the first prize at the speech competition, ______?
23.I had reached a point in my career _____ I needed to decide which way to go.