Natural Medicines

Since earliestdays,humans have used some kinds of medicines.We know this because humans have

survived.Ancienttreatments for injury and disease were successful enough to keep humans fromdying out

completely.

They were successfullong before the time of modern medicine.Before the time of doctors with white

coats and shiny（发亮的）instruments. Before the time ofbig hospitals with strange and wonderful equipment.

Many parts of theworld still do not have university-educated doctors. Nor do they have expensivehospi-

tals.Yet injuriesare treated.And diseases are often cured.How?By ancient methods.By medicinesthat

might seemmysterious , even magical（有魔力的）.Traditional medicines are neither mysterious nor magical,

however.

Through thecenturies, tribal（部族的）medicinemen experimented with plants. They found many use-

ful chemicals in theplants.And scientists believe many of these traditional medicines may providethe cure

for some of today'smost serious diseases.

Experts say almost80% of the people in the world use plants for health care.These naturalmedicines

are used not justbecause people have no other form of treatment.They are used because peopletrust them.

In developedareas,few people think about the source of the medicines they buy in astore.Yet many wide-

ly-used medicinesare from ancient sources,especially plants.Some experts say more than 25% ofmodern

medicines come,inone way or another,from nature.

Scientists have longknown that nature is really a chemical factory.All living things containchemicals

that help themsurvive.So scientists' interest in traditional medicine is not new.But it hasbecome an ur-

gent concern.This isbecause the earth's supply of natural medicines may be dropping rapidly.It can be seenfrom the passage that the earth's supply of natural medicines________.

A.may never beexhausted

B.may be droppingrapidly

C.is surprisingly big

D.is as rich as ever