单项选择题A.He can’t prepare for the exam.B.He doesn’t think he needs to take the exam.C.John will take the exam instead of him.D.John will help him during the exam.
单项选择题A.To find out whether there is life in the deep water.B.To help better understand the water area of the earth.C.To learn more about the marine life.D.To find out how many sea animals there are in the sea.