阅读理解。
Australian scientists are trying to give kangaroo-style stomachs to cattle and sheep in order to cut the
greenhouse gases they send out, which is thought to be responsible for global warming.
Thanks to special bacteria in their stomachs, kangaroo flatulence (肠胃气胀) contains no methane (甲烷)
and scientists want to transfer that bacteria to cattle and sheep who produce large quantities of the harmful
gas.
While the usual image of greenhouse gas pollution is a billowing smokestack (烟囱) pushing out carbon
dioxide, farm animals' passing wind contribute a surprisingly high percentage of total emissions (排放物) in
some countries. "Fourteen percent of emissions from all sources in Australia is from enteric methane from
cattle and sheep," said Athol Klieve, a senior research scientist with the Queensland state government.
"And if you look at another country such as New Zealand, which has got a much higher agricultural base,
they're actually up around 50 percent," he said.
Researchers say the bacteria also makes the digestive process much more efficient and could potentially
save millions of dollars in feed costs for farmers.
But it will take researchers at least three years to isolate (分离) the bacteria, before they can even start to
develop a way of transferring it to cattle and sheep.
Another group of scientists, meanwhile, has suggested Australians should farm fewer cattle and sheep and
just eat more kangaroos. And about 20 percent of health-conscious Australians are believed to eat the national
symbol already.
"It's low in fat, it's got high protein levels and it's very clean in the sense that basically it's the free-range
(放养的) animal," said Peter Ampt of the University of New South Wales's institute of environmental studies.
1. Scientists intend to put bacteria into cattle and sheep _____.
A. to prevent them from sending out harmful gases
B. to help Australian farmers to earn more money
C. so that they can protect Australian ecosystem
D. so that they can make full use of special bacteria
2. Athol Klieve seems to believe that _____.
A. cattle and sheep produce more carbon dioxide
B. less cattle and sheep are raised in New Zealand
C. farm animals are to blame for greenhouse gases
D. New Zealand has the most animals in the world
3. The main idea of the text is to _____.
A. discuss a better way to protect the earth
B. warn farmers of the danger of animal waste
C. illustrate the possible solutions to pollution
D. present a recent study on global warming
4. The advantages Peter Ampt lists about kangaroos don't include _____.
A. it is rich in protein
B. is low in fat
C. it is cheaper than beef
D. it is cleaner than sheep