单选题Water is the only substance that occur at ordinary temperatures in all three A B C states of matter: solid, liquid and gas. D

单选题.Although many people use the word “milk” to refer cow’s milk, _______ to milk from any animal, including human milk and goat’s milk.

单选题Listen to Track 52. A. To correct a misstatement he made about the Sahara's climate B. To suggest that the current dryness of the Sahara is exaggerated C. To indicate that scientists are not in agreement about the Sahara's past climate D. To emphasize the difference between the current and past climates of the Sahara

单选题The word "convert" line 6 is closest in meaning to

单选题Endemic diseases are diseases that habitual infect only those persons living within certain geographical limits.

单选题The word "remarkable" in line 14 is closest in meaning to

单选题The word "intermittently" in live 4 is closest in meaning to

单选题The passage implies that the warmest temperatures among the periods mentioned occurred

单选题The mechanism of human thought and recall, a subject only partly understood by scientists, A B C is extraordinary complicated. D

单选题Gravitation keeps the Moon in orbit around Earth and the planets other of the solar system in A B C orbit around the Sun. D

单选题According to the author, all of-the following evidence relating to the first birds was found EXCEPT

单选题Stereo recording began with the introductory of two-track magnetic tape in the 1950’s. A B C D

单选题Abundant rainfall or irrigation is necessary during the early growperiod of coffee, but dry conditions during ripening produce beans with the best flavor.

单选题The word "some" in line 14 refers to

单选题Listen to Track 6. A. To suggest that United States citizens have not changed much over time B. To encourage the class to find more information about this time period C. To explain why Emerson's essay has lost some relevance D. To provide background for the concept he is explaining

单选题He makes ＄20 an hour, has more work than he can handle.

单选题The work of Sarah Oarne Jewet, care-nineteenth-century writer, reflects a concern in {{/U}}the alienating consequence, of condustrialization {{/U}}and urbanization.

单选题(Over) the course of history, (much) civilizations developed (their own) number (systems). A. Over B. much C. their own D. systems

单选题by 1872 the United States had 70 engineering colleges, ______astonishing expansion credited largely to the Morrill Act of 1862. A. because B. an C. to which D. was

单选题 THE FIVE—SEVEN SHIFT1 All major theories of child psychology state that children undergo a major change between the ages of five and seven. In classical learning theory, this is a time when the simplest forms of learning give way to learning that involves more complex mental processes. According to psychologist Jean Piaget, the period from five to seven years old is a transition to operational thought, when children are able to move beyond using only their senses toward using a new set of rational-thinking skills. Because several cognitive changes occur in children between ages five and seven, this period is called the five-seven shift. The shift is biological in nature and involves fundamental growth in the brain and stabilization of brain-wave rhythms into a basically adult pattern. The five-seven shift involves many physical changes, such as the loss of the "baby teeth" and an increase in the rates of height acquired and weight gained. 2 By the time they are five years old, children can understand and use symbols. They have developed the ability to use {{U}}words, gestures, and pictures{{/U}} to stand for "real life" objects, and they are skilled in deploying various symbol systems, such as language or drawing. However, a five-year-old child is able to focus attention on only one quality of an object at a time, such as the object's size or shape. The use of symbolization continues to evolve, reaching a {{U}}peak{{/U}} around the age of seven or eight, when children become capable of concrete operations. When this happens, they can solve problems by using rational thought to make generalizations from their own experience. 3 By the age of seven or eight, a new set of abilities allows children to reason systematically about the world of objects, quantity, time, space, and causality. According to Piaget, this is because an "extra card" is added to the child's mental "computer" during the five-seven shift. The development of operational thought enables the child to appreciate the relations among a series of actions upon objects. For example, the child understands that a scene can be viewed from a different perspective and still contain the same elements. The child also understands that objects can be rearranged and still have the same quantity and that a substance can be changed in shape without its mass or volume being affected. 4 Piaget discovered the most widely known {{U}}hallmark{{/U}} of the five-seven shift, an understanding of conservation, the idea that some properties stay the same despite changes in appearance. In one of Piaget's classic experiments on the conservation of quantity, the experimenter shows children of different ages two straight rows of coins, each with six coins pressed close together, beside each other on a table. The experimenter asks each child subject whether both rows have the same number of coins or whether one row has more. Then the experimenter spreads out the coins of one row to make the line look longer. The child must now say whether one row has more coins. {{U}}Children younger than five years old cannot understand conservation, so they invariably say that the spread-out row has more coins than the other row. {{/U}}5 Like most age-related tasks for children, there are other ways to set up the task. In a similar experiment, water is poured into two identical glasses until the child subject agrees that each contains an equal amount. Then the experimenter pours water from one of these glasses into a tall, thin glass. At that point, the child is asked whether one glass has more water than the other. Five-year-old children will say that there is more water in the tall, thin glass. When asked why they think that, many will confidently say, "Because it's taller." Older children, however, are likely to reply, "It looks like there's more water in this one because it's taller, but they're really the same." Such experiments show a difference between children of five years and children of eight years. The older children can solve the task promptly, easily, under a wide variety of conditions, and without being taught. The younger children, even if they are taught about conservation, cannot do what the five-seven shift will do for them naturally: provide them with a more developed brain.Glossary: cognitive: relating to mental processes