考研英语听力基本功训练1: Passage27

Of the more than 80 million children born every year in the developing countrie

and estimated 5 million die

and at least twice as many are disabled by disease which have been largely eliminated in developed nations through immunizatio

In the Sudan,the large country in Afric

less than 10% of the children are vaccinated against diseases such as measle

polio,whooping cough,diphtheria,tetanus and tuberculosi

all of which can kill or disable the unprotected chil

They CAN be protected but supplying vaccine is not enoug

A successful immunization programme depends on a crucial factor-the COLD CHAI

Without a system of storage and distribution which keeps the vaccine below the critical 8

the vaccine deteriorates and its power is los

The problem of establishing a cold chain is particularly acute in a hot country like the Sud

where the distances the vaccine must travel are so vast.