What do you know about the sea? Some people often see it, _______ others don’t. The sea looks beautiful _______ a fine sunny day. Millions of people hope _______ their holidays by the sea. They can swim in or lie (躺) on the beaches in the sun. They enjoy themselves there. But it can be very terrible _______ there is a strong wind you know about _______?

Of course, the sea is very large. Looking _______ a map of the world, you can see it is much bigger than land. There _______ a lot of islands in the sea. Some are big and some are small.

Did you _______ in the sea? If you answer “Yes”, you may know that the water is salty. Rivers _______ salt from the land to the sea. Some places of the sea are saltier than other places. Do you know the Dead Sea (死海)? Fish can’t live in it. However, ________ is afraid to sink (下沉) in the Dead Sea. Why? Because people would float (漂浮) in it.