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| 文章出处：学生大考试站 发布时间：2005-10-12 |
tened to his son's explanation
D) he received the signal himself with the machine
75. What is implied in the passage?
A) Guglielmo was better than his brother in science.
B) His father was so fascinated by his invention that he proposed to
join them.
C) Guglielmo discovered that a spark can make other waves travel.
D) Morse Code was invented by the Marconi brothers.
Questions 76 to 80 are based on the following passage:
Yellow fever is a disease of warm lands that is found mainly along theshore of the Atlantic Ocean. It was first noticed in the Americas, but maywell have come form Africa and reached the New World with or soon afterColumbus. Until about fifty years ago, yellow fever was still one of themost feared diseases in the United States, where many died in repeated out-breaks. An outbreak which was to lead to surprising developments was onethat happened in Cuba during the Spanish-American War.
As a result, an army group under Major Walter Reed was sent there inJune, 1900 with orders "to give special attention to questions concerningthe cause and prevention of yellow fever". In a daring group of experimentsusing human beings, Major Reed proved the truth of an idea advanced in 1881by a Cuban doctor, that the city type of mosquito passed on the disease.
The successful result of these experiments gave birth to another andstill more important idea: kill off the city type of mosquitoes and therewill be no more yellow fever. Fortunately these mosquitoes are one of theeasiest types to destroy. They are born in pools of quiet, warm water,within a short distance to people's home.
So to Havana came a General with orders from the United States Govern-ment to dry up these pools. He carried out his task so well that the mos-quitoes disappeared. With them went yellow fever, never to return to Havana.A few years later the same General successfully repeated this operation inPanama and in this way made possible the building of the Panama Canal. Itall seemed so simple. End the mosquitoes: end the disease. Man even beganto dream of getting rid of yellow fever from the world.
Meanwhile one question still remained unanswered. The city type of mosquitoes carried the fever, without doubt, but how? After many experi-ments, a member of the United States Army Yellow Fever Commission decidedthat the disease must be carried by something too small to be seen. Ofhis
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