A．food production must be increased
B．fresh water supply must be supervised more carefully
C．the growth of population must be controlled
D．the waste of food and water must be restricted

A．more and more fresh water is used by farmers for their crops
B．the amount of fresh water that can be used for crops decreases
C．the earth will become wanner and wanner
D．the ability to use fresh water sources becomes restricted

A．The world will need 60% more food．
B．The world will need 60% more fresh water．
C．The world's population will increase 17%．
D．Fresh water will be in short supply in many countries．