CLOZE TESTS without key (8 pages) Mã A681228

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CLOZE TESTS

1. The first two decades of this century were dominated by the microbe hunters.

These hunters had tracked (1) _______________ one after another of the

microbes responsible for the most dreaded scourges of many centuries:

tuberculosis, cholera, diphtheria. But (2) _______________remained some terrible

diseases for which no microbe could be incriminated: scurvy, pellagra, rickets,

beriberi. Then it was discovered that these diseases were (3) _______________ by

the lack of vitamins, a trace substance in the diet. The diseases could be prevented

or cured by consuming foods that contained the vitamins. And so in the (4)

_______________of the 1920's and 1930's, nutrition became a science and the

vitamin hunters replaced the microbe hunters.

In the 1940's and 1950's, biochemists strived to learn (5) _______________each

of the vitamins was essential for health. They discovered that key enzymes in

metabolism depend on one or (6) _______________of the vitamins as coenzymes

to perform the chemistry that provides cells with energy for growth and function.

Now. these enzyme hunters occupied center stage.

You are aware that the enzyme hunters have been replaced by a new breed of

hunters who are tracking genes - the blueprints for each of the enzymes - and are

discovering the defective genes that cause (7) _______________diseases -

diabetes, cystic fibrosis. These gene hunters, or genetic engineers, use

recombinant DNA technology to identify and clone genes and (8)

_______________them into bacterial cells and plants to create factories for the

massive production of hormones and (9) _______________for medicine and for

better crops for agriculture. Biotechnology has become a multibillion dollar (10)

_______________.

2. Situated in the central mountains of Alaska, a peak named Denali rises 20,320 feet

above sea level. It is the (1) _______________peak in North America and the

center of Denali National Park. One of America's greatest wilderness areas, the

park has had (2) _______________access to visitors, but 5 in spite of this tourism

rose from under 6,000 visitors in 1950 to over 546,000 visitors in 1990. The

increasing (3) _______________of this park is prompting serious discussions

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about the future use of Denali as well as how to preserve wilderness areas in (4)

_______________.

One important issue of land use arises when parts of National Parks are owned by

individuals. In Denali, (5) _______________most of the land in this vast tract of

more than a million acres is owned by the National Park Service, several thousand

acres are still (6) _______________owned as mining tracts. These mining tracts in

Denali were once abundant sources of gold, but they were sources of (7)

_______________metals such as arsenic and lead that polluted rivers and

streams.

Environmentalists were successful in getting the government to require mining

companies to submit statements showing the potential impact 20 of a mining

project before they are (8) _______________to begin mining. Because of this

requirement, many individuals closed their mines and some sold their land to the

National Park Service. Some land owners, (9) _______________, are wondering if it

is better to sell their land to the government or keep it for possible future use.

Tourism in this previously remote 25 area is bound to rise, as more roads are built

to provide easier access to the park. This increase in the number of visitors creates

a demand for hotels and other real estate development. The economic implications

of this are of (10) _______________to the land owners, but are dismaying to those

interested in preserving the wilderness.

3. It’s the curse of online clothes shopping. You come across a shirt you simply must

have, (1) _______________to find that what you receive doesn’t fit (2)

_______________being in your size. How can you order clothes (3)

_______________confidence when you can’t try them on?

A new wave of …