单项选择题
He is（）about his chances of winning a gold medal in the Olympics next year.
A.optimistic B.optional C.outstanding D.obvious
单项选择题 We agreed to accept（）they thought was the best tourist guide.
单项选择题 Wouldn't you rather your child（）to bed early?
单项选择题 Before they left the factory, all the cars were carefully tested for（）
