第4部分：阅读理解(第31～45题，每题3分，共45分)

　　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。

　　第一篇

　　31. what is the main idea of this passage?

　　a. public lands are one of the main sources of revenues.

　　b. public lands should be developed to ease energy shortage.

　　c. public lands play an important role in energy production.

　　d. public lands store huge energy resources for further development.

　　32. which of the following statements is true of public lands in the u.s.?

　　a. half of us energy is produced there.

　　b. most of coal was produced from there in 2000.

　　c. most energy resources are reserved there.

　　d. the majority of undiscovered natural gas is stored there.

　　33. geothermal resources, wind turbines, and hydropower facilities in paragraph 4 are cited as examples to illustrate that

　　a. alternative energy production is no less than conventional energy production.

　　b. they are the most typical conventional energy resources from public lands.

　　c. geothermal resources are more important than the other two.

　　d. the amount of alternative energy production from public lands is huge.

　　34. there is a mounting pressure on public lands to satisfy us energy demands because

　　a. many americans are unhappy with energy development in foreign countries.

　　b. the u.s. is demanding more and more energy.

　　c. quite a few public lands are banned for energy development.

　　d. many americans think public lands are being abused.

　　35. public lands can be used for energy development when

　　a. they go through the land use planning process.

　　b. energy development restrictions are effective.

　　c. federal land managers grant permissions.

　　d. there is enough federal budget.

　　第二篇

　　when our eyes serve our stomach

　　all we have a clock located inside our brains. similar to your bedside alarm clock, your internal clock2 runs on a 24-hour cycle. this cycle, called a circadian rhythm, helps control when you wake, when you eat and when you sleep.

　　somewhere around puberty, something happens in the timing of the biological clock. the clock pushes forward, so adolescents and teenagers are unable to fall asleep as early as they used to. when your mother tells you it's time for bed, your body may be pushing you to stay up3 for several hours more. and the light coming from your computer screen or tv could be pushing you to stay up even later.

　　this shift4 is natural for teenagers. but staying up very late and sleeping late can get your body's clock out of sync with the cycle of light and dark5. it can also make it hard to get out of bed in the morning and may bring other problems, too. teenagers are put in a kind of a gray cloud6when they don't get enough sleep, says mary carskadon, a sleep researcher at brown university in providence, ri7. it affects their mood and their ability to think and learn.

　　but just like your alarm clock, your internal clock can be reset. in fact, it automatically resets itself every day. how? by using the light it gets through your eyes.

　　scientists have known for a long time that the light of day and the dark of night play important roles in setting our internal clocks. for years, researchers thought that the signals that synchronize the body's clock8 were handled through the same pathways that we use to see.

　　but recent discoveries show that the human eye has two separate light-sensing systems. one system allows us to see. the second system tells our body whether it's day or night.

　　36. "poorer children" and "hungry people" are mentioned in paragraph 2 to show

　　a. humans' senses are influenced by what's going on in their heads.

　　b. they have sharper senses than others.

　　c. they lose their senses because of poverty and hunger.

　　d. humans' senses are affected by what they see with their eyes.

　　37. there was a delay in radel's experiment because

　　a. he needed more students to join.

　　b. he didn't prepare enough food for the 42 students.

　　c. he wanted two groups of participants, hungry and non-hungry.

　　d. he didn't want to have the experiment at noon.

　　38. why did the 80 words flash so fast and at so small a size on the screen?

　　a. to ensure the participant was unable to perceive anything.

　　b. to guarantee each word came out at the same speed and size.

　　c. to shorten the time of the experiment.

　　d. to make sure the participant had no time to think consciously.

　　39. radel's experiment discovered that hungry people

　　a. were more sensitive to food-related words than stomach-full people.

　　b. were better at identifying neutral words.

　　c. were always thinking of food-related words.

　　d. saw every word more clearly than stomach-full people.

　　40. it can be learnt from what radel says that

　　a. humans' thinking processes are independent of their senses.

　　b. an experiment with hungry and non-hungry participants is not reliable.

　　c. humans can perceive what they need without deep thinking processes.

　　d. 42 participants are too small a number for a serious investigation.

　　第三篇

　　41. this passage deals mainly with

　　a. famous names in ballet.

　　b. how ballet has developed.

　　c. russian ballet.

　　d. why ballet is no longer popular.

　　42. the word "pageants" in paragraph 2 means

　　a. big shows.

　　b. dances.

　　c. instructions.

　　d. royal courts.

　　43. professional ballet was first performed in

　　a. france.

　　b. italy.

　　c. russia.

　　d. america.

　　44. who had an important influence on early ballet?

　　a. balanchine.

　　b. antoinette.

　　c. diaghilev.

　　d. louis xiv.

　　45. we can conclude from this passage that ballet

　　a. is a dying art.

　　b. will continue to change.

　　c. is currently performed only in russia.

　　d. is often performed by dancers with little training.