时间就象时钟一样无时无刻不在我们的内耳中滴答作响。

A．Drugs are always given to animals for medical reasons.
B．Some of the additives in our food are added to the food itself and some are given to the living animals.
C．Researchers have known about the potential hazards of food additives for over thirty-five years.
D．Food may cause forty percent of cancer in the world.