单选题Why does life on earth depend much on the oceans?A Sea plants produce most of the oxygen in the atmosphere.B Carbon dioxide is converted into oxygen in oceans.C The oceans provide an invaluable food resource.D Productivity of fisheries can feed 80 mill
题目
单选题
Why does life on earth depend much on the oceans?
A
Sea plants produce most of the oxygen in the atmosphere.
B
Carbon dioxide is converted into oxygen in oceans.
C
The oceans provide an invaluable food resource.
D
Productivity of fisheries can feed 80 million people.