填空了!16、My son,you need to learn how to make your own _______

填空了!
16、My son,you need to learn how to make your own _______ ( decide) .
17、This old vase is ________________ ( valuable ) than that one.
18、Do you know the ________________ ( science) symbol for water?
19、It is raining _________________ ( hard ) outside.
20、He _______( remove ) the fish from the bird and put it into the basket.