what do you know about the sea? some people know about it, but others don't. the sea looks beautiful on a fine sunny day, but when there's a strong wind, it's very rough. what else do you know about it?

　　of course, the sea is very big. in the world, there is more sea than land. do you know hainan island? it's really very nice. we can see beaches, trees and the sea. we can swim and visit a lot of beautiful places.

　　when you swim in the sea, you feel that the water is salty.

　　at last, i tell you about the dead sea. fish can't live in it, because it's dangerous. this sea is too salty.

　　the sea is nice, but sometimes it's not good.