To make the best and the most efficient use of your time and to achieve your goals, start each day by （ ）your agenda.
A.holding on B.making out C.keeping on D.taking down
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To make the best and the most efficient use of your time and to achieve your goals, start each day by （ ）your agenda.
Petrified wood consists of a wide variety of mineral including silica, silicates, carbonates, sulfates, sulfides, oxides, and phosphates. They all can per-mineralize wood to form petrified wood. However, petrified wood most commonly consists of silica in the form of either opal or chert. Silicified wood is usually found within one of two types of strata. First, it occurs within accumulations of volcanic ash, tuff, ad breccia, e.g. the petrified forests of Yellowstone National Park. Second, silicified wood also occurs within sands, silts, and muds deposited by rivers and streams that have hardened to sandstones, siltstones, and shale. The silicified wood found in Petrified Forest National Park in Arizona and the Miocene strata of Louisiana and Texas occur within such strata. It forms in these deposits, because of the presence of dissolved silica within the groundwater. The silica is derived from the dissolution of the volcanic material by the groundwater within the sediments. Within 10 and 40 million years, the opal of the silicified wood further dehydrates and crystallizes into microcrystalline quartz (chert). Factors such as temperature and pressure may speed or slow the process, but eventually the opal of the silicified wood becomes chert. During the change from opal to chert in silicified wood, the relict woody texture may either be retained or lost.In southwest Texas and into Louisiana, three types of silicified wood can be recognized. First, the “nondescript silicified wood” is one that possesses a recognizable woody structure. It is not identifiable without oriented thin sections, specialized references, and comparative material. Therefore, this type is best described just as “silicified wood”. The second type, “Palm Wood”, is a group of fossil woods that contain prominent rod-like structures within the regular grain of the silicified wood. Depending upon the angle at which they are cut by fracture, these rod-like structures show up as spots, tapering rods, or continuous lines. The third type is “massive silicified wood” in which the silicification of the wood, or subsequent transformation of silica gel to opal or chert, has obliterated any trace of the grain of the former wood. Because of its variable, massive nature and heterogeneous trace element composition, many investigators have often failed to recognize the nature of this material.1.What does the passage mainly discuss?2.Which of the following is commonly a part of petrified wood?3.The underlined word “strata” in Paragraph 1 is closet in meaning to （ ）.4.It can be inferred from the passage that which of the following is true of Yellowstone National Park?5.The underlined word “such” in Paragraph 1 refers to （ ）.6.The author mentions groundwater (the underlined word) in Paragraph 1 in order to（ ）.7.According to the passage, the opal of the silicified wood became chert because （ ）.8.In paragraph 2, the author discuss three types of silicified wood because （ ）.9.The underlined word “prominent” in Paragraph 2 is closet in meaning to （ ）.10.Which of the following is a description, rather than one of the three type of silicified wood?11.What is the reason why many investigators have often failed to recognize the third type of silicified wood?
Are undergraduate grades important? Everyone knows that high marks earned at different schools or under different instructors can indicate very different levels of achievement. One professor may be a hard grader, while another is very generous or one who takes the whole business as a bit of joke. Some schools have nigh standards, whereas others are groups of intellectual people. And at all universities, there is a constant tendency towards grade inflation （the granting of ever more high marks）. That is fought vigorously at some institutions and allowed to go unchecked for long periods at others.Another point raised against grades is how poorly they predict how much graduates will be earning 15 or 20 years after getting their degrees. As many studies have shown, there is only a very poor correlation between undergraduate’s grades and subsequent wealth. People who get good marks tend to go into the professions, not all of which are highly remunerative（有利的）.The correlation between undergraduate grades and success in business, the most common road to wealth, is virtually nothing. Many mediocre（平庸）students become successful businessman, while some brilliant and capable graduates （creative youngsters, not students with special skills in passing exams） take up relatively low-paying but interesting or satisfying careers. The general population, examining this question through a statistical lens, sees one thing very clearly that good grades don’t translate in any direct way into big bucks, and for better or for worse, the gauge（标尺） of “success” for countless Americans is the acquisition of wealth.The result is a certain modesty about good grades in America among those who get them. A student’s parents may brag about his marks, but seldom will the student himself risk being branded a “grade-grubber” by drawing too much attention to his academic success. High marks are not something to be advertised to the world except on resumes, and anybody who boasts about them is likely to be viewed with contempt, not least by intelligent people.1.Which of the following is true about undergraduate grades?2.According to the passage, what is the relationship between grades and business performance?3.Which of the following best describes the American attitude towards good grades?4.The phrase “grade-grubber”, underlined in paragraph 3 probably means （ ）.5.What might be the best title for this passage?
Why does cream go bad faster than butter? Some researchers think they have the answer, and it comes down to the structure of the food, not its chemical composition—a finding that could help rid some processed foods of chemical preservatives.Cream and butter contain pretty much the same substances, so why cream should sour much faster has been a mystery. Both are emulsions—tiny globules （小球体）of one liquid evenly distributed throughout another. The difference lies in what’s in the globules and what’s in the surrounding liquid, says Brocklehurst, who led the investigation.In cream, fatty globules drift about in a sea of water. In butter, globules of a watery solution are locked away in a sea of fat. The bacteria which make the food go bad prefer to live in the watery regions of the mixture. “This means that in cream, the bacteria are free to grow throughout the mixture.” He says.When the situation is reversed, the bacteria are locked away in compartments buried deep in the sea of fat. Trapped in this way, individual colonies cannot spread and rapidly run out of nutrients. They also slowly poison themselves with their waste products. “In butter, you get a self-limiting system which stops the hotelier growing.” Says Brocklehurst.The researchers are already working with food companies keen to see if their products can be made resistant to bacterial attack through alterations to the food’s structure. Brocklehurst believes it will be possible to make the emulsions used in salad cream, for instance, more like that in butter. The key will be to do this while keeping the salad cream liquid and not turning it into a solid lump.1.The significance of Brocklehurst’s research is that（ ）.2.According to the researchers, cream sours faster than butter because bacteria （ ）.3.According to Brocklehurst, we can keep cream fresh by （ ）.4.The word ‘‘colonies’’ refers to （ ）.5.Commercial application of the research finding will be possible if salad cream can be made resistant to bacterial attack（ ）.
At midnight, he drove through streets（ ）of traffic.
W: Would you like me to get you some tea?M: Not now, thanks. Maybe later.Q: What does the man want?
