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Someday, rice plants might provide not only food but also a way to prevent cholera（霍乱） and other diseases.

Cholera is a deadly disease found mostly in Africa, Asia and Latin America today. Current vaccines（疫苗） to protect against cholera must be kept in refrigerators, which limits use in poor countries.

But research in Japan may lead to rice plants that contain a cholera vaccine that does not need to be kept cold. So far, they have experimented only on mice. Their findings were published earlier this month.

Hiroshi Kiyono of the University of Tokyo and his team researched into the bacterium（细菌） responsible for cholera. They placed it into the Kitaake rice plant.

Mice ate the rice seeds as a powder. The report says the vaccine was not destroyed by stomach acid; instead, the animals developed antibodies against cholera. The scientists say the vaccine remained active even after being stored at room temperature for more than a year and a half.

Cholera is usually spread through water or food, in the places where conditions are dirty and drinking water supplies are unsafe. The WHO says half of the infected patients will die if they aren’t treated properly.

The researchers have great hopes for rice-based vaccines as a way to protect large populations against cholera infections. There would be no need for injection, since the vaccine would be taken by mouth.

68. Cholera vaccines aren’t commonly used in poor countries now because         .

A. the weather is too hot

B. patients can’t afford to buy them

C. they have side effects

D. they must be stored in refrigerators

69. What happened after mice ate the genetically changed rice power?

A. They got infected with cholera bacterium.

B. They produced antibodies against cholera.

C. The vaccine was destroyed by stomach acid.

D. The scientists didn’t notice any change.

70. It can be inferred that in the future         .

A. people would take drugs containing the powder as a vaccine

B. people would have injection to develop antibodies against cholera

C. cholera infections would become popular in the world

D. more vaccines to be taken by mouth would be developed

71. What is the best title of the text?

A. New vaccines against cholera              

B. Don’t be afraid of cholera any more

C. Growing rice and a cholera vaccine at the same time

D. The findings made by the University of Tokyo

责任编辑:yingyubao