单选题Listening1"Professor'sOffice"

单选题The phrase "tantamount to" in line 7 is closest in meaning to

单选题Which of the following statements is best supported by paragraph 4? (a) Agricultural development contributed to development in other parts of the economy. (b) European agricultural products were of a higher quality than those produced in the United States. (c) The growing settlement of the West led to a decrease in agricultural production. (d) Farmers were influenced more by government policies than by market opportunities.

单选题Many meteorites are thought to have originated from _____ that once existed between the orbits of Mars and Jupiter.

单选题Listentopartofalectureinananatomyclass.Nowgetreadytoanswerthequestions.Youmayuseyournotestohelpyouanswer.

单选题Genes Until only just a few centuries ago, people believed that the genes of the parents blended together and resulted in the exact same genetic makeup. Then, in the early 1800s, Gregory Mendel, a renowned Austrian scientist, discovered that only certain traits such as the shape of the nose, or a particular eye color are passed directly from parent to child. Because of his work, and the work of many scientists since, we now know that many of our physical and behavioral characteristics are determined by genetic factors which have been handed down to us from our parents and grandparents. We also know that our genes, as well as our lifestyle, are behind many common diseases that afflict us as individuals. The genes we inherit from our parents program our development from conception to adulthood. In each cell, we have about 90,000 pairs of genes arranged on 23 pairs of chromosomes, one of the pair being maternal and the other being paternal. Although our brothers and sisters inherit genes from the same parents, the mixture of genes is slightly different in each sibling. It is the reason every organism is different. Each gene provides instructions to a cell to carry out a single chemical process; it also controls the growth and reproduction of multiple cells. Genes are thus responsible for the development of the embryo into a baby and a child, then eventually into an adult. Throughout our lives, genes control cell function and the repair and replacement of damaged or dead cells. Blood relatives have many genes in common, and these genes help to determine family physical characteristics and other traits. Most of these traits, such as the shape of the nose, are trivial and have no significant effect on health. Other traits, such as being abnormally short or tall, or having a tendency to be overweight, can be associated with an increased risk of certain diseases. Some diseases, such as hemophilia and cystic fibrosis, are directly caused by a mutation in a single gene or a pair of genes. These rare diseases follow a predictable pattern of inheritance, and this means that families in which the gene is present can usually be given clear, reliable information regarding the risk of the disease affecting their future offspring. Therefore, gene therapy holds great promise for the cure of diseases, and researchers will eventually come up with a way to regulate abnormal gene behavior without disrupting normal ones. Some, gene therapists have looked at viruses as a way to cure certain diseases. However, viruses replicate easily and move around the body to interact with other genes, so a virus that is used to cure hemophilia can replicate and enter an area where a tumor gene is located and stimulate it to cause a cancer. Gene therapy using bacterial DNA yields opposite results. More common than these genetic disorders are those in which genes, along with other factors, contribute to a family"s susceptibility to certain diseases. For example, some disorders, such as coronary artery disease, tend to run in families, but lifestyle factors such as a high-fat diet, smoking, and lack of exercise also play a part in determining whether these diseases develop. In some diseases that have a genetic component, including asthma, environmental factors, such as living in a polluted area, also play a crucial role. Cancer is not caused simply by one gene, but rather it is a result of a whole variety of circumstances. In a lab, mice were genetically altered to include a gene that causes tumors in the retina of the eye in humans, but surprisingly, none of the animals developed any symptoms of this disorder. Such complex interplay between genetic susceptibility and environment makes it difficult to predict the risks in adult life for children who are born into families affected by disorders of this kind. We are now aware of the fact that we are susceptible to diseases passed through families, and that our lifestyles can serve to exacerbate symptoms and or bring about the early onset of say heart disease. The good news is that we can use this information to arm ourselves against diseases brought on by an unhealthy lifestyle, if we know that our genes carry a likelihood of us developing heart disease then it would be prudent to try to live a healthy lifestyle. Glossary conception: the act of becoming pregnant; fertilization of an ovum by a spermatozoid chromosome: a thread-like body in the cell nucleus that carries the genes in a linear order embryo: an organism in its earl) stages of development, especially before it has reached a distinctively recognizable form hemophilia: congenital tendency to uncontrolled bleeding; usually affects males and is transmitted from mother to son cystic fibrosis: the most common congenital disease, the child"s lungs and intestines and pancreas become clogged with thick mucus; caused by defect in a single gene coronary artery: the artery that branches from the aorta to supply blood to the heart

单选题Newspaper publishers in the united states have estimated ___________reads a newspaper every day.

单选题1 The cells of a plant are organized into three tissue systems: dermal, vascular, and ground tissue. Each tissue system is continuous throughout the plant's body. The specific characteristics of each tissue, however, are different in the different organs of the plant. 2 The dermal tissue system is the "skin" of the plant. The dermal system, or epidermis, is a single layer of cells covering the entire body of the plant. The main function of the epidermis is to protect the plant. The epidermis also has specialized chamcteristics for the particular organs it covers. For example, the epidermis of leaves and stems has a waxy coating that helps the plant conserve water, and the epidermal cells near the tips of the plant's roots help the plant absorb water and nutrients from the soil. 3 The second tissue system--the vascular system--is the transportation system for water and nutrients. Vascular tissue also helps to support the plant's structure. The third system-- the ground tissue--makes up the bulk of a plant, filling all of the spaces between the dermal and vascular tissue systems. Ground tissue functions in photosynthesis, storage, and support.

单选题Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary of characteristics by selecting the THREE answer choices that express the most important ideas in the passage. Some sentences do not belong in the characteristics. This question is worth 2 points. Philosophers of logical analysis appreciate human intellect more than others. ● ● ● Answer ChoicesA. Philosophers of logical analysis make mathematics mystical.B. They do more research on metaphysics.C. These philosophers pretend that deep-stated prejudices are heaven-sent intuitions.D. They incorporate mathematics to develop a powerful logical technique.E. They believe that science and human intellect are of great importance.F. They do not believe that there is some higher way of knowin

单选题Native to South America and cultivated there for thousands of years, the peanut is said to have introduced to North America by early explorers.

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单选题The pear tree has simple, oval leaves that are smoother and shinier than them of the apple.

单选题.The carbon-are lamp, a very bright electric lamp used for spotlights, consists of two carbon A B electrodes with a high-current are passing between it. C D

单选题Paleoanthropologists examine fossil remains of extinct primates, while physical anthropologists concernwith ethnology study the behavior of primates intheir natural settings.

单选题1 Animal behaviorists believe the orangutan is a cultured ape, able to learn new living habits and to pass them along to the next generation. Some orangutan parents teach their young to use leaves as napkins, while others demonstrate the technique of getting water from a hole by dipping a branch in and then licking the leaves. Orangutans have been observed saying goodnight with the gift of a juicy raspberry. Such social interactions lead researchers to conclude that if orangutans have culture, then the capacity to learn culture is very ancient. 2 In the evolutionary timeline, orangutans separated from the ancestors of humans many millions of years ago, and they may have had culture before they separated. The discovery of orangutan culture suggests that early primates--including ancestors of humans--might have developed the ability to invent new behaviors, such as tool use, as early as 14 million years ago, approximately 6 million years earlier than once believed.

单选题(Researchers) have found subtle neurological (differences) between the brains of men and women (either) in physical structure and in (the way) they function.

单选题(Due to) persistent inbreeding, self-pollinating plants (have) genetically more uniform than cross-pollinated plants,(which) harbor more genetic (variability).

单选题Ruth Bader Ginsburg argued six women's rights cases before the United States Supreme Court in the 1970's,____

单选题NorthAmericanGrasslandsInNorthAmerica,nativegrasslandsoccurprimarilyintheGreatPlainsinthemiddleofthecontinent.TheNorthAmericanprairiebiomeisoneofthemostextensivegrasslandsintheworld,extendingfromtheedgeoftheRockyMountainsinthewesttothedeciduousforestintheeast,andfromnorthernMexicointhesouthtoCanadainthenorth.Averageannualrainfallrangesfromabout40cm(16inches)inthewestto80cm(31inches)intheeast.Averageannualtemperaturesrangebetween10degreesand20degreesCelsius(50to68degreesFahrenheit).InthemoistregionsoftheNorthAmericangrasslands,especiallyinthenorthernGreatPlains,rainfallisdistinctlyseasonal,andtemperaturescanvarywidelyfromveryhotinsummertobittercoldinwinter.Onehundredyearsago,theGreatPlainsgrasslandswereonevast,unbrokenprairie.Muchoftheprairieisnowfarmland,themostproductiveagriculturalregionintheworld,dominatedbymonoculturesofcerealgrains.Wheat,barley,soybeans,corn,andsunflowersoccupythelandthatwasonceprairie.Inareasgivenovertograzinglandsforcattleandsheep,virtuallyallthemajornativegrasseshavebeenreplacedbyalienspecies.AnimportantfeatureofthenorthernGreatPlainsgrasslandsisthepresenceofmillionsofglacialdepressionsthatarenowsmallpondsknownasprairiepotholes.TheywereformedduringthemostrecentIceAge,whenstreamsflowedintunnelsbeneathglaciallyformedsandyridges.WhentheIceAgeendedaround12,000yearsago,theretreatingglacierscreatedabout25milliondepressionsacrossa300,000-square-milelandscape--about83potholespersquaremile.Astheiceblocksmelted,muchofthewaterwasleftbehind,formingwetlandsranginginsizefromatenthofanacretoseveralacres.Thewetlandsweresoonsurroundedbyflutteringwavesofgrasses:shortgrass,mixedgrass,andtallgrass.Todaythesesmallwetlandsstillcovertheprairies,althoughmuchofthelandscapeincludingbothnativegrassesandpotholeshasbeentransformedtocroplandandgrasslandforgrazing.Whatdoesremainofthewetlands,however,stillservesasanimportantbreedingareaformorethan300birdspecies,includinglargenumbersofmigratingshorebirdsandwaterfowl.Thepotholesfillupwithwaterduringspringrainsandusuallydryoutbylatesummer.Everyspring,birdsarriveingreatnumbers--northernpintails,mallards,coots,andpied-billedgrebes--4to6millionstrong,tomateintheseasonalwetlandsthatdotportionsofMinnesota,Iowa,NorthandSouthDakota,Montana,Alberta,Saskatchewan,andManitoba.PrairiepotholecountryproduceshalfofNorthAmerica's35to40millionducksandisrenownedworldwideasa"duckfactory".Recentlybiologistshavediscoveredthattheprairiepotholeregionispotentiallyavastcarbonsink:anaturalspongethatabsorbscarbondioxideemissionsfromcars,factories,andpowerplants.Carbondioxideisthemostcommonofallthepollutantsactingasgreenhousegasesthatheatuptheatmosphere.Fortunately,however,carbondioxideiscapturednaturallyandstoredintrees,soil,andplants.Scientistshavetermedthis"carbonsequestration".Theyhavedeterminedthatprairiepotholesholdanaverageof2.5tonsofcarbonperacreperyearwhennotbeingfarmed.ThismeansthatiftheentirepotholeregionintheUnitedStatesandCanadaweretostopbeingfarmed,theregionwouldstoreabout400milliontonsofcarbonover10years--theequivalentoftakingalmost4millioncarsofftheroad.Thus,preservingthepotholescouldbeawaytooffsetgreenhousegasemissionsthatarewarmingtheplanet.Glossary:biome:oneoftheworld'smajornaturalcommunities,classifiedbypredominantvegetationmonoculture:cultivationoflargelandareaswithasingleplantvariety