单选题She was one of the leading writers of her day. A. expected B. natural C. most important D. least

单选题Since ancient times people have found various ways to Upreserve/U meat.

单选题 下面有3篇短文，每篇短文后有5道题。请根据短文内容，为每题确定1个最佳选项。{{B}}第一篇{{/B}} Prolonging Human Life Prolonging human life has increased the size of the human population. Many people alive today would have died of childhood diseases if they had been born 100 years ago. Because more people live longer, there are more people around at any given time. In fact, it is a decrease in death rates, not an increase in birthrates that has led to the population explosion. Prolonging human life has also increased the dependency load. In all societies, people who are disabled or too young or too old to work are dependent on the rest of society to provide for them. In hunting and gathering cultures, old people who failed to follow the others were left behind to die. In times of famine, infants might be allowed to die because they couldn't survive if their parents starved, whereas if the parents survived they could have another children, in contemporary societies, people feel a moral obligation to keep people alive whether they can work or not. We have a great many people today who live past the age at which they want to work or are able to work; we also have rules that require people to retire at a certain age. Unless these people were able to save money for their retirement, somebody else must support them. In the United States many retired people live on social security cheeks that are so little that they must live in near poverty. Older people have more illness than young or middle-aged people; unless they have wealth or private or government insurance, they must often "go on welfare" if they have a serious illness. When older people become senile or too weak and ill to care for themselves, they create grave problems for their families. In the past and in some traditional cultures, they would be cared for at home until they died. Today, with most members of a household working or in school, there is often no one at home who can care for a sick or weak person. To meet this need, a great many nursing homes and convalescent hospitals (康复医院)have been built. These are often profit-making organizations, although some are sponsored by religious and other nonprofit groups. While a few of these institutions are good, most of them are simply "dumping grounds" for the dying in which "care" is given by poorly paid, overworked, and under skilled personnel.

单选题Even in a highly modernized country, manual work is still needed.A. expressiveB. physicalC. exaggeratedD. dubious

单选题Our new house is on the first floor.

单选题Compared with large aircraft, small airplanes are not as streamlined and {{U}}hence{{/U}} are less efficient.

单选题We found （shelter） from the rain under the trees.

单选题In the United States, the need to protect plant and animal species has become a highly controversial and sharply political issue since the passage of the Endangered Species Act in 1973. The act, designed to protect species' living areas, and policies that preserve land and forests compete with economic interests. In the 1990's, for example, the woodcutters in the Western United States were challenged legally in their attempt to cut trees for timber in the Cascade Mountains. The challenge was mounted to protect the endangered spotted owl(猫头鹰), whose remaining population occupies these forests and requires the intact, ancient forest for survival. The problematic situation set the interests of environmentalists against those of corporations and of individuals who stood to lose jobs. After months of debate and legal battles, the fate of the woodcutters—and the owls—was still undecided in mid-1992. Similar tensions exist between the developed and the developing nations. Many people in industrialized nations, for example, believe that developing nations in tropical regions should do more to protect their rain forests and other natural areas. But the developing countries may be impoverished(使穷困), with populations growing so rapidly that using the land is a means to temporarily avoid worsening poverty and starvation. Many of the changes to Earth that concern scientists have the potential to rob the planet of its biological richness. The destruction of Earth' s ozone layer(臭氧层), for example, could contribute to the general process of impoverishment by allowing ultra-violet rays to harm plants and animals. And global warming could wipe out species unable to quickly adapt to changing climates. Clearly, protecting will come only through coordinated international efforts to control human population, stabilize the composition of the atmosphere, and preserve intact Earth' s complex web of life.

单选题These are our motives for doing it.

单选题She gave up her job and started writing poetry.

单选题Students working toward a degree in business are {{U}}likely{{/U}} candidates for careers in the banking industry.

单选题We bad a long conversation about her parents. A. speech B. question C. talk D. debate

单选题The team's Uspirit/U was at the lowest point in the season.

单选题 A. short-term memory B. relearning C. needed D. coded E. recognition F. slow forgetting rate

单选题Many experts remain {{U}}skeptical{{/U}} about his claims. A. doubtful B. untouched C. certain D. silent

单选题Image Martian Dust Particles NASA's Phoenix Mars Lander has taken its first ever picture of a single particle of rusty Martian dust with one of its microscopes. The dust particles of dust were shown at a higher magnification than anything outside of Earth that has been imaged before. The rounded particle measured only about one micrometer, or one millionth of a meter, across. "Taking this image required the highest resolution microscope operated off Earth and a specially designed device to hold the Martian dust," said Tom Pike, a Phoenix science team member from Imperial College London. "We always knew it was going to be technically very challenging to image particles this small." The device that imaged the dust speck is called an atomic force microscope, which maps the shape of particles in three dimensions by scanning them with a sharp tip at the end of a spring. The atomic force microscope can detail the shapes of particles as small as about 100 nanometers. And this won't be the last dust particle that Phoenix will image. "After this first success, we're now working on building up a portrait gallery of the dust on Mars," Pike said. Dust exists everywhere on Mars, coating the surface and giving it its rusty red color. Dust particles also color the Martian sky pink and feed storms that regularly envelope the planet. The ultrafine dust is the medium that actively links gases in the Martian atmosphere to processes in Martian soil, so it is critically important to understanding Mars' environment, the researchers said. The $ 420-million Phoenix mission is analyzing the dust and subsurface ice layers of Mars' arctic regions to look for signs of potential past habitability. The particle seen in the atomic force microscope image was part of a sample scooped by the robotic arm from the "Snow White" trench and delivered to Phoenix's microscope station in early July.

单选题How do you (account) for your absence from the class last Thursday?

单选题John survives on 100 pounds a month. A. puts B. lives C. borrows D. spends

单选题Thinking of the interesting stories helped the time to pass, and the work seemed less Utough/U.

单选题Unfortunately, the new swine flu virus can be transmitted between humans. It is not clear yet how easily it is transmitted, nor how it is transmitted. Almost surely it is transmitted by sneezing and coughing, and by skin-to-skin contact with an infected person. How is the swine flu virus transmitted according to the passage?A. It is very easily transmitted from person to person.B. It is not quite sure how it is transmitted yet.C. It is surely transmitted by sneezing or coughing.D. It is surely transmitted by skin-to-skin contact.