单项选择题A.Wait for the lecture to begin.B.Go immediately to their seats.C.Get something to drink first.D.Sit down and enjoy the lecture.
单项选择题A.7:30 to9:00 a.m.B.4:00 to 6:30 p.m.C.7:00 to 9:30 a.m.D.3:30 to 5:30 p.m.