What´s the main idea of the text? -考呗网

英语六级

单选题 What´s the main idea of the text?

A．A more productive soybean is found to solve the future food shortages.
B．Scientists have done many researches to deal with food shortages.
C．Soybeans are the only solution to solve the food shortages.
D．There will be a great food shortage in 2050.

参考答案：A进入在线模考

主旨题。这篇短文主要讲的是科学家发现了新的大豆可以解决未来的粮食短缺问题。B、D选项不够准确。C选项是错误的，大豆是目前发现的一种方法，不一定是唯一方法。因此，正确答案是A。

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1Questions are based on the following passage.
The huge growth of global "ecotourism" industry is becoming an increasing concern for con servationists with mounting evidence that many wild species do not respond well to contact with human beings. Over exposure to tourists has been linked to stress, abnormal behaviour and adverse health effects in species such as polar bears, dolphins and gorillas, says a report in New Scientist.
"While regulated ecotourism can help conservation efforts by encouraging people to manage endangered species and their habitats, many projects are poorly designed and unregulated," it says.
"Many ecotourism projects are unaudited, unauthorized and merely hint they are based on environmentally friendly policies and operations."
Ecotourism is growing by 10 to 30 percent a year and an estimated 20 percent of tourists are thought to visit a conservation-based project. Philip Seddon, of the University of Otago in New Zealand, said that although most tourist projects conformed to basic guidelines on land use and not scaring wildlife, their full impact was rarely considered.
"Transmission of disease to wildlife or subtle changes to wildlife health through disturbance of daily routines or increased stress levels may translate to lowered survival and breeding" he said. Re- search at the University of Auckland has shown that dolphins become restless and overactive when many tourist boats are present. When three or more boats are near, the dolphins rest for 0.5 percent of the time, compared with 68 percent when they are accompanied by a single boat. The findings are backed up by studies of dolphins in Britain. Researchers at the University of Manitoba in Canada have found that male polar bears were easily disturbed by tourist vehicles, with a possible effect on their heart rate and metabolism. That could reduce body fat levels and fitness, which are critical for survival.
In Africa, gorillas have picked up parasites introduced to their habitat by tourists and mongooses have caught lung diseases from human beings. Experts said that the answer to the problems was better regulation and supervision of ecotourism. The Galapagos Islands, where visitor numbers are strictly controlled, is a good model.
What can we know from the first paragraph?

A．Conservationists are strongly in favour of the development of "ecotourism" industry.
B．It is found that some wild species could be badly affected by over contact with people.
C．The huge growth of global ecotourism industry has a very bad effect on the environment.
D．Ecotourism is good for encouraging people to protect endangered wild species.

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2According to New Scientist, many ecotourism projects ___________.

A．really encourage people to protect wildlife and its habit
B．strictly follow environmentally friendly polices
C．actually lack proper examination and official approval
D．seriously damage the habitats of endangered species

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3 What dose Phillip Seddon think of most tourist projects?

A．They should be prohibited by government totally.
B．They are beneficial to the environmental conservation.
C．They always go against the basic guidelines on land use.
D．They seldom take their whole effect into consideration.

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