初中英语推断题Because about 97％ of water on the earth is sea water

初中英语推断题
Because about 97％ of water on the earth is sea water which we can not drink or use for watering plants directly.Man can only drink and use 3％ ---the water that comes from rivers and lakes .And we can not even use all of that ,because some of it has been polluted
Now more water _______.The problem is:Can we avoid a serious water shortage later on?First,we should all learn how to reuse water.
A needs B is needing C is needed needed D has been