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．
A．The victory over one's fellow runners．
B．The victory over former runners．
C．The victory of will-power over fatigue．
D．The victory of one's courage over illnesses．