A．He invented a concentrated syrup for headache．
B．He invented cola as a soft drink．
C．He transformed cola to a soft drink．
D．He made a lot of money from cola．

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