听下面5段对话或独白。每段对话或独白后有几个小题，从题中所给的A、 B 、C三个选项中选出最佳选项，并标在试卷的相应位置。听每段对话或独白前，你将有5秒钟的时间阅读各个小题；听完后，各小题将给出5秒钟的作答时间。每段对话或独白读两遍。
What do you know about the River Nile [A] It’s the largest river in the world. [B] It often flooded large areas. [C] It’s the second longest river in the world.