Around 200 million years ago, the earth was 18 degrees warmer than it is now. That might be a bit hot for humans, but it was just right for the giant dinosaurs that wandered about the earth during the Mesozoic era. A new study found that planteating dinosaurs may have contributed to the warming of the earthby releasing significant amounts of methane . The study, published in science journal Current Biology, focused on sauropods, longnecked herbivores that munched on the top of trees. They were the largest of the dinosaurs; food broke down in their stomachs for long periods of time. The researchers estimate that a sauropoda released 2,675 liters of methane per day--adding up to a large amount of the greenhouse gas being pumped from dinosaur's gut into the atmosphere. Plant eaters naturally release methane as part of their digestive process. The larger the animal, the more methane it produces. Methane, a greenhouse gas, traps heat and remains in the atmosphere for approximately 915 years, which warms the atmosphere. Today, some animals, such as cattle, goats and sheep, produce large amounts of methane as a byproduct to their food digestion. Methane is also released from human--influenced sources such as landfill, agricultural activities, coal mining and other industrial practices--which all contribute to today's climate change, according to the Environmental Protection Agency. The researchers estimate that earth's sauropods would have produced about 520 million tons of methane per year--similar to the total amount of methane produced today by natural and manmade sources. However, the researchers warn that their numbers are estimates based on multiple assumptions about the digestive systems and populations of dinosaurs. The author of the study David Wilkinson says the emission of methane from dinosaurs would have been just one of the causes of warm climate during the Mesozoic era. Other causes include gases produced from volcanoes, swamps, shallow seas and so on. Still,... David Wilkinson seems to believe that _ . A) methane had little effects on the earth B) many other factors contributed to warm climate C) other causes for warm climate were worth considering D) dinosaurs were mainly to blame for global warming
B
Film 1 -- The environmental problems in South Africa This film will take you on a wonderful trip deep into the South African forests and across four decades of research to experience the changes in the environment in South Africa. With no roads or airstrips nearby, the waterways are the only choice for reaching the great forests. This unbelievable journey invites you to be among the few humans who have dared to go to the South African forests to examine the different disappearing creatures and plants of South Africa. Place: Cheerful Theatre Admission Fees: Front Stalls $30, Stalls $38 (Standard) Front Stalls $15, Stalls $19 (Concession) Note: 1. Concessions are applicable to senior citizens aged 60 or above. 2. Children under 3 years old will not be admitted. Duration: 50 minutes Show Dates: April1 - May 31 Discount: With the cash coupons offered by K&S Ltd., you can now enjoy a 50% discount on the $38 ticket and pay only $19 per head. Film 2 -- The climatic changes in India This film will take you to the mysterious land of India. This film features a scientist, Nina, who set out alone on a five-year journey across the country. Along the way, Nina experiences the harshness of India's land, which contains every type of natural environment on Earth -- from the freezing temperatures of the Himalayas to the extremely hot deserts, and to dense tropical rainforests. The film shows how she survives the tough journey in India. Place: Glorious Theatre Admission Fees: Front Stalls $50, Stalls $70 (Standard) Note: Children under 3 years old will not be admitted. Duration: 120 minutes Show Dates: May 15 - May 31, only one show every day from 1 p.m. to 3 p.m. Not on show at weekends. Special Feature: Good news for those who are interested in India! With the purchase of any two tickets at $70 each, you can join our prize-winning competition to win 2 round-trip tickets to India! Film 3 -- The power of nature This film features inspiring and frightening atmospheric and geological events. It shows how we can help... What do the three films have in common? A) They have an age limit. B) They last longer than 120 minutes. C) They are only on show at weekends. D) They offer a discount.
A
Q: The publication of "Harry Potterandthe Half-Blood Prince" gladdens booksellers across China. The British and American editions were No. 1 and No. 3 respectively on the sales chart of the Beijing Xidan Book Building last week. The book's poster is highlighted and news about the book can often be heard on the radio. Why is the book so attractive to children? With curious mood, the author got a copy of "Harry Potter". Originally, I wanted to glance over it and made some criticisms. But, out of expectation, the author has been deeply attracted by the magic world. On the other hand, one cannot help asking: _ Harry Potter"? The Chinese nation has a history of 5, 000 years, which cannot be regarded as short and its culture as not profound. With a vast market of youngsters, China did publish many books popular among children. However, why are the present works not as good as those imported? There come two major reasons: Firstly, quite a number of children's books are of strong sense of teaching, and lack interest and entertainment. Children often have a feeling of being "educated". No wonder they don't like them. Secondly, children's reading materials involving "idiom stories" and "Chinese talents' stories", though always in different covers, are usually much the same or plagiarized . One knows the ending as early as in the beginning. In final analysis, the authors of the books seldom take children's requirements into consideration. As a matter of fact, each child has his own wonderful imagination. They long to understand the world and nature. Similarly they have their own choices. They dislike similar stories, even if the stories are excellent. First-class reading for children should be very interesting, which contains knowledge and the essence of national culture, which are presented in children's language. Market is a touchstone for products. The theory also holds true for cultural products. It is hoped that the authors of children's books can learn something from the good market of "Harry Potter" and write out... The reason why the imported book is so popular is that _ . A) it has no sense of teaching B) it opens a wonderful world for children to explore C) it is only written in children's language D) it is advertised more on TV or poster.
A: B