第三部分:阅读理解(共20小题;每小题2分,满分40分)

阅读下列短文,从每题所给的四个选项(A、B、C和D)中,选出最佳选项,并在答题卡上将该项涂黑。

WASHINGTON(AP)—Good news for dinosaur fans:There are probably a lot more of them waiting to be discovered.At least,their fossils are.

Peter Dodson of the University of Pennsylvania and Steve Wang of Swarthmore College estimate that 71 percent of all dinosaur genera(种类)—groups of dinosaur species—have yet to be discovered.

“It’s a safe bet that a child born today could expect a very fruitful career in dinosaur paleontology(古生物学),”Dodson said in a statement.

The estimate appears in Tuesday’s issue of Proceedings of the National Academy of Sciences.

Dodson—a professor of anatomy at Penn’s School of Veterinary Medicine and professor at Penn’s Department of Earth and Environmental Sciences—first estimated the potential number of dinosaur genera in 1990 and is revising that upward.

The estimates are based on the rates of discovery—about 10 to 20 annually—and the recent increase in finds of fossils in China,Mongolia and South America.

Dodson suggests that 1,850 genera will eventually be discovered.So far 527 genera have been found.

Fossilization itself is a rare event,they note,and as many as half of the dinosaur genera that ever existed may have left no remains.

“I would never suggest that this predictionhowever statistically(统计上地)soundis the final word on dinosaur diversity,“Dodson added.”My intention is to fuel the discussion using the facts at hand,and this is the best estimate we can make with the data available.”

56.The best title for the passage would be______________.

A.Much more dinosaur once lived on the earth

B.Good news for dinosaur fans

C.A very fruitful career in dinosaur paleontology

D.Dinosaurs remain to be discovered

57.Who made the first estimate about the possible number of dinosaur genera?

A.The author of the passage.           B.Steve Wang.

C.Peter Dodson.                                          D.Both B and C.

58.Which of the following statements is NOT mentioned in the passage?

A.The number of dinosaur fans is getting larger and larger.

B.More dinosaur fossils are expected to be found in future.

C.The estimate was based on plenty of facts of dinosaur paleontology.

D.Not all the dinosaur genera left their fossils.

59.It can be inferred from the text that______________.

A.dinosaurs will return to the world once again

B.about 3700 dinosaur genera once lived on the earth

C.only half of the dinosaur fossils have been found so far

D.all dinosaur fossils have been find in China.Mongolia and South America

60.The underlined sentence in the last paragraph most probably means____________.

A.Enough research work has been done on dinosaur diversity

B.it is probable that more information about dinosaur diversity will be found in future

C.the conclusion drawn by Dodson is not exactly right

D.Dodson will continue his research work on dinosaur diversity

Many people think the search for cleaner energy leads only to renewable resources like sun, wind and water. But it also leads to a fossil fuel. Natural gas is considered the cleanest of the fossil fuels, the fuel created by plant and animal remains over millions of years. Burning it releases fewer pollutants than oil or coal. The gas is mainly methane (甲烷). It produces half the carbon dioxide of other fossil fuels. So it may help cut the production of carbon gases linked to climate change.

Russia is first in what are called "proved reserves" of natural gas. The United States is sixth. Over the years, big oil and gas companies recovered much of the easily reached supplies of gas in America. They drilled straight down into formations where gas collects. As these supplies were used up, big drillers looked for similar formations in other countries.

But now the industry is taking a new look. Companies are developing gas supplies trapped in shale (页岩) rock two to three thousand meters underground. They drill down to the shale, then go sideways and inject high-pressure water, sand or other material into the rock. This causes the rock to fracture, releasing the gas. Huge fields of gas shale are believed to lie under the Appalachian Mountains, Michigan and the south-central states. Gas shale exploration is being done mainly by small to medium sized companies. Eric Potter, a program director, says more than half the gas in the United States is now coming from these new reserves.

But hydraulic (液压的) fracturing can also produce debate and anger over the risk of groundwater pollution. This method of drilling is not federally supervised under the Safe Drinking Water Act. Some in Congress want to end that exemption (豁免) from the law.

Natural gas provides Americans with about one fourth of their energy. And, unlike oil, most of it is produced in America. Gas producers invested heavily in reaching new supplies when prices were high. But prices are down sharply now because the depression cut demand for energy. So energy expert Eric Potter says it is too early to know how the changing market prices will affect the market for gas shale exploration.

68. We can learn from the first paragraph that ________.

   A. natural gas releases methane and carbon dioxide

   B. natural gas is considered as the cleanest energy

   C. natural gas is more environmentally friendly than other fossil fuels

D. natural gas is a renewable source of energy

69. The word “fracture” in Paragraph 4 probably means _______.

   A. create       B. break              C. change             D. decrease

70. Gas shale exploration may cause disagreement because ______.

   A. it may cause water pollution   B. it brings too high profits

   C. it breaks the law              D. it is out of states’ control

71. According to Eric Potter, the new gas shale exploration ______.

   A. will provide America with about one fourth of their energy

   B. will increase demand for energy

   C. will make gas producers invest a big sum of money

   D. may be influenced by the changing market prices

 0  29951  29959  29965  29969  29975  29977  29981  29987  29989  29995  30001  30005  30007  30011  30017  30019  30025  30029  30031  30035  30037  30041  30043  30045  30046  30047  30049  30050  30051  30053  30055  30059  30061  30065  30067  30071  30077  30079  30085  30089  30091  30095  30101  30107  30109  30115  30119  30121  30127  30131  30137  30145  151629 

违法和不良信息举报电话:027-86699610 举报邮箱:58377363@163.com

精英家教网