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．
A．It is the best known long distance race in the world．
B．It is the biggest Marathon race in the U．S．
C．It was first held 50 years ago．
D．It attracts nearly 5000 official competitors in recent years．
A．He won the first prize．
B．He died because of fatigue．
C．He fell behind the other runners．
D．He gave up because he was fired．