题目内容
（请给出正确答案）
Scientists ______that bacteria through microscopes for many years．
A．studied
B．have studied
C．had studied
D．have seen studied
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更多“Scientists ______that bacteria through microscopes for many years．A．studiedB．have studiedC”相关的问题
According to the text, the UK scientists have known that______.
A．women have more cells than men when they are born
B．women can replace the cells that enable the heart to beat
C．the female heart loses few of the cells with age
D．women never lose their pumping power with age
It can be inferred from the passage that scientists of the 18th century _______.
A．knew that they were ignorant and wanted to know more about nature
B．were afraid of facing up to the realities of scientific research
C．thought that they knew a great deal and could solve most problems of science
D．did more harm than good in promoting man's understanding of nature
听力原文： Pet owners are being encouraged to take their animals to work. Scientists say that can be good for productivity, workplace morale, and the well-being of animals.
A study found that 25% of Australian women would like to keep an office pet. Sue Chaseling of Petcare Information Service said the practice of keeping office pets was good both for the people and the pets. "On the pets' side, they are not left on their own and won't feel lonely and unhappy," she said. A study of major U.S companies showed that 73% found office pets beneficial, while 27% experienced a drop in absenteeism.
Xarni Riggs has two cats walking around her Global Hair Salon in Paddington. "My customers love them. They are their favorites," she said. "They are not troublesome. They know when to go and have a sleep in the sun. "
Little black BJ has spent nearly all his two years "working" at Punch Gallery in Balmain. Owner Iain Powell said he had had cats at the gallery for 15 years. "BJ often lies in the shop window and people walking past tap on the glass," he said.
Ms. Chaseling said cats were popular in service industries because they enabled a point of conversation. But she said owners had to make sure both their co-workers and the cats were comfortable.
Questions 29 to 31 are based on the passage you have just heard.
29. What is the percentage of American companies that are in favor of keeping office pets？
30. What do we know about "BJ" from the passage？
31. Which would be the best title for this passage？
(30)
A．15%.
B．25%.
C．27%.
D．73%.
Tha bag ______ books ______ mine.
A．full of; are
B．full of; is
C．full in; are
Some states have an income tax similar to ______ of the federal government。
A. tha。
B. those
C. this
D. these
A.When
B.While
C.Unless
D.Until
Efforts to Protect the Environment
Most scientists agree that if pollution and other environmental deterrents (威慑) continue at their present rates, the result will be irreversible (不能倒转的) damage to the ecological cycles and balances in nature upon which all life depends. Scientists ware that fundamental, and perhaps drastic, changes in human behavior. will be required to avert (转移) an ecological crisis.
To safeguard the healthful environment that is essential to life, humans must learn that Earth does not have infinite resources. Earth's limited resources must be conserved and, where possible, reused. Furthermore, humans must devise new strategies that mesh environmental progress with economic growth. The future growth of developing nations depends upon the development of sustainable conservation methods that protect the environment while also meeting the basic needs of citizens.
Many nations have acted to control or reduce environmental problems. For example, Great Britain has largely succeeded in cleaning up the waters of the Thames and other rivers, and London no longer suffers the heavy smogs caused by industrial pollutants. Japan has some of the world's strictest standards for the control of water and air pollution. In Canada, the Department of Commerce has developed comprehensive programs covering environmental contaminants.
In the United States, the Environmental Protection Agency (EPA) was established in 1970 to protect the nation's natural resources. In addition, the U.S. Congress has provided governmental agencies with legislation (立法) designed to protect the environment. Many U.S. states have also established environmental protection agencies. Citizen groups, such as the Sierra Club and the National Audubon Society, educate the public, support environment-friendly legislation, and help assure that federal and state laws are enforced by pointing out violations.
A. Environmentalism in the United States
In the United States the modern environmental movement is rooted in a 19th-century New England philosophical movement called transcendentalism (超验主义), whose leaders included the poet and essayist Ralph Waldo Emerson and the naturalist and author Henry David Thoreau. In their writings, both men expressed a reverence for the natural world, believing that humans and nature shared a divine spirit. Emerson asserted that nature was eternal and capable of recovering from mistreatment at the hands of humans. Thoreau, more protective and pessimistic, has been quoted as saying, "Thank God, men cannot yet fly and lay waste the sky as well as the earth."
Although Emerson and Thoreau wrote eloquently about the value of nature and its spiritual importance to humans, neither of them undertook a systematic analysis of the effects that humans have on their environment. That task was left for 19th-century American diplomat George Perkins Marsh. In 1864 Marsh published Man and Nature; or, Physical Geography as Modified by Human Action, considered the first book to demonstrate that human activity could cause dramatic and irreversible damage to Earth. Marsh explained how some agricultural practices had led to deforestation (采伐森林), loss of wetlands, desertification (the process of land becoming desert), species extinction, and changes in weather patterns.
In the early 20th century, U.S. president Theodore Roosevelt greatly expanded both the national forest and national park systems and created a system of national wildlife refuges. Roosevelt appointed forestry expert Gifford Pinchot as head of the U.S. Forest Service, and together they molded the foundation of the American conservation movement, developing methods for the sustainable use and protection of natural resources. Roosevelt and Pinchot recognized that even the vast natural resources of the United States were not limitless and thus had to be managed carefully, and they believed tha
A．Y
B．N
C．NG
A.Now that
B.Seeing that
C.Whether
D.Supposing that
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