单项选择题A.They have been working at the telescope for two days.B.They can’t find the microscope.C.They’ve been working in the laboratory for two hours.D.They can’t fix the microphone.
单项选择题A.He finds it worthwhile to take the initiative in making friends.B.He considers college is not a perfect place to make real close friends.C.He often meets difficulties of certain kind in making friends.D.He finds college life helps him become more optimistic.