单选题The local newspaper has a ______ of 10,000 copies a day. A. manipulation B. combination C. reproduction D. circulation

单选题When did the first Chinese reach the U.S.?

单选题 {{B}}TEXT A{{/B}}{{B}} Mind Your Calories or Your Waistline?{{/B}} Cutting back the calories may do more than whittle your waistline; it could protect your brain from the effects of aging. A new study suggests that calorie restriction can help slow the normal process of cell death that happens with age. Researchers say the body naturally goes through a process known as apoptosis, or cell death, to destroy old cells so new ones can be made, and many factors can alter this process. Age-related diseases, such as Alzheimer's and Parkinson's, cause a higher-than-normal loss of cells in the brain, which can lead to loss of function. Previous studies have suggested that calorie restriction can boost life span and mental capacity. That prompted researchers to look at whether cutting calories might also play a role in protecting aging brain cells. They compared levels of proteins indicating brain cell death in two groups of rats. One group was given unrestricted access to food and water throughout their lives. The other was given 40% fewer calories (but still adequate nourishment) than the unrestricted group. They found that the levels of these proteins increased with normal aging in the rats fed unrestricted diets. The rats given a restricted diet did not have an increase in the levels of these proteins. Another protein thought to protect from cell death dropped by 60% in the well-fed rats, but it actually increased over time in the calorie-restricted rats. Finally, DNA fragmentation, a third indicator of cell death, more than doubled in the unrestricted rats with age, but this increase was 36% less in the calorie-restricted rats. Although the results are promising, researchers say more study is needed to completely understand the processes that lead to cell death and the role nutrition plays in that process. Meanwhile, they say, their study provides yet another reason to watch what you eat. "We're not going to do it right away to improve our memories; we're going to do it probably in general for the first reasons, which would be to prevent cardiovascular disease and cancer," says Christian Leeuwenburgh at the University of Florida.

单选题By 1929, Mickey Mouse was as popular ______ children as Coca-Cola. A. for B. it C. one D. among

单选题Drinking a little alcohol during pregnancy is just fine for most women, found a new study. "Heavy drinking has been (31) for a long time with difficulties for mothers and the children born to them," said lead researcher Yvonne Kelly. " However, there hasn't been a (32) research to look at the lower end of the drinking range," she added. The study, which found no (33) of harm for pregnant women from having (34) drinks a week, was so well done and its findings (35) conclusive that it ought to become the final word in the (36) said Fred Bookstein, a researcher who studies alcohol (37) He hopes that research dollars can now go towards finding the effects of more (38) chemicals. In the United Kingdom, mothers (39) to have a relatively relaxed attitude toward alcohol during pregnancy. (40) a third of pregnant women report drinking at least some alcohol, Kelly said, (41) a natural experiment to look at how levels of drinking (42) children later on. When the babies were 9 months old, morns were asked to describe how much alcohol they had (43) during pregnancy. Then, the babies took a series of tests that evaluated their behavioral, (44) and intellectual development. The kids took similar tests at age three and again at age five. Final results of the study agreed (45) previous work that children born to heavy drinkers do worst on developmental tests, because excessive (46) to alcohol in the womb kills nerve cells and causes brain damage. But the study found no evidence (47) light drinking during pregnancy causes emotional or learning problems in children (48) the age of five. In some tests of vocabulary and pattern creation, (49) , boys actually did best if their morns drank a little while carrying them. The findings (50) what the researchers had found when the kids were three years old.

单选题Humidity is so intense in some parts of the tropics that Europeans find they are unable to ______ it. A. maintain B. persist C. endure D. sustain

单选题______ of the two books holds the opinion that the danger of unemployment is increasing. A. None B. Both C. Either D. Neither

单选题The police have asked for the ______ of the public in tracing the whereabouts of the missing boy.

单选题Fashion magazines and TV advertisements seem to link fashion to ______.

单选题We delayed our departure______ bad weather.[A] on account of[B] to account of[C] with account of[D] for account of

单选题Your ideas, ______ , seem unusual to me.

单选题After the theft of his car he put in an insurance ______ for $4500.

单选题Each year, more US properties within floodplains are destroyed by flooding than fire. Changing weather patterns, increased urban development, and the leveling of forests have reduced the land's natural ability to absorb water. As flooding becomes a common occurrence, property owners need to face the facts. Flood damage can happen anytime, no matter where you live. Flood insurance, which is financially backed by the US Government through the National Flood Insurance Program, is available through Homesite Insurance and the Homesite Insurance Agency. The National Flood Insurance Program (NFIP) through the Federal Emergency Management Agency is the primary provider of flood insurance. The Homesite Insurance Company acts as a " Write-Your-Own" company on behalf of the NFIP. "Write-Your-Own" companies sell and service flood policies and the NFIP pays the claims. Property owners know a Homeowners policy covers fire damage, but most don't realize that it won't cover flood or mudslide damage. Rising waters and debris can destroy your home, business, and personal belongings within minutes. Most floods don't qualify for federal disaster aid. Only floods that are declared national disasters by the President qualify for federal assistance. This assistance is in the form of a grant averaging less than $2,500, or a federal loan that must be paid back with interest. That's in addition to payments on your existing mortgage loan! Only flood insurance protects your home and you," belongings from damage caused by rising water or mudflow. Flood insurance is available for the value of the structure minus the land value. Contents coverage is also available, but is optional and must be requested. Even if you've had previous flooding, you can still buy flood insurance. If you've received disaster assistance before, you must first obtain flood insurance to be eligible for future federal relief. The average flood policy is only $324 a year—that's less than $1 a day. Compare that to a typical disaster loan of $50,000, costing more than $300 a month for over 18 years! Flood insurance pays all covered claims even if a federal disaster is not declared. Claims are paid quickly so victims can recover faster. You can even get a partial payment right away to get started. Flood coverage is available up to $250,000 for your home, and up to $100,000 for the contents. Anyone can buy flood insurance if his/her property is located in a community that participates in the National Flood Insurance Program. Homes, condos, apartments, and business structures are all eligible. Even renters may purchase flood insurance for their possessions. Since flood premiums are set by the US government, your rate is the same from any insurer.

单选题where does the woman have to go at 12:30?

单选题You'd better add them up. I'm not good at______.A. figuresB. charactersC. summariesD. counters

单选题It is quite common for a working man to make ______ for his old age by putting aside enough money to live on. A.adjustment B.supply C.assurance D.provision

单选题 {{B}}TEXT A{{/B}} Renewable energy sources can be replenished in a short period of time. The five renewable sources used most often include hydropower (water), solar, wind, geothermal, and biomass. Renewable energy's impact on the world's energy picture is significant. Many important events have occurred during the history of using renewable sources to generate electricity--but the overall consumption from renewable energy sources has declined by about 15 percent from their I996 peak to about 6 quads in 2005. The use of renewable energy is not new. Five generations (125 years) ago, wood supplied up to 90 percent of our energy needs. Due to the convenience and low prices of fossil fuels, wood use has fallen. Now, the biomass which would normally present a disposal problem is converted into electricity (e.g., manufacturing wastes, rice hulls, and black liquor from paper production). Historically, low fossil fuel prices, especially for natural gas, have made growth difficult for renewable fuels. The deregulation and restructuring of the electric power industry could have a major impact on renewable energy consumption. Demands for cheaper power in the short term would likely decrease demand for renewable energy, while preferences for renewables included in some versions of proposed electricity restructuring legislation would breathe new life into this industry. Use of renewables in the United States is not currently expected to approach that of the major fuels, and due to their limitatious (e.g., their intermittent nature-cloudy days have no solar gain, quiet days mean no wind blows to drive wind turbines, dams are primarily for flood control, so hydroelectricity production varies as dams' water levels change), renewables may never provide "the" answer to all energy problems. Around the world, renewable energy is proving to be of great value. In 2005, about 6.1 Quadrillion Btu (Quads) of U.S. energy came from renewable fuels. Each of the energy sources we use is measured, purchased, and sold in a different form. Many units of measurement are used to measure the energy we use each day.

单选题If you want to get into that tunnel, you first have to ______ away all the rocks.