【正文】 hedule, but all were assigned to it by their supervisors.C. Working ten hours a day has allowed the most productive employees to work two hours alone each day in their respective offices relatively undisturbed by fellow employees.D. Employees at SaleCo are pensated not on the basis of how many hours a week they work but on the basis of how productive they are during the hours they are at work.E. Those SaleCo employees who have a fourday workweek do not take any of their office work to do at home on Fridays.GWD6Q22:Charles Lindbergh, for his attempt at a solo transatlantic flight, was very reluctant to have any extra weight on his plane, he therefore refused to carry even a pound of mail, despite being offered $1,000 to do so.A. Charles Lindbergh, for his attempt at a solo transatlantic flight, was very reluctant to have any extra weight on his plane, he thereforeB. When Charles Lindbergh was attempting his solo transatlantic flight, being very reluctant to have any extra weight on his plane, heC. Since he was very reluctant to carry any extra weight on his plane when he was attempting his solo transatlantic flight, so Charles LindberghD. Being very reluctant to carry any extra weight on his plane when he attempted his solo transatlantic flight was the reason that Charles LindberghE. Very reluctant to have any extra weight on his plane when he attempted his solo transatlantic flight, Charles LindberghGWD6Q23 to Q26: Diamonds are almost impossible to detect directly because they are so rare: very rich kimberlite pipes, the routes through which diamonds rise, may contain only three carats of diamonds per ton of kimberlite. Kimberlite begins as magma in Earth’s mantle (the layer between the crust and the core). As the magma smashes through layers of rock, it rips out debris, creating a mix of liquid and solid material. Some of the solid material it brings up may e from a socalled diamondstability field, where conditions of pressure and temperature are conducive to the formation of diamonds. If diamonds are to survive, though, they must shoot toward Earth’s surface quickly. Otherwise, they revert to graphite or burn. Explorers seeking diamonds look for specks of “indicator minerals” peculiar to the mantle but carried up in greater quantities than diamonds and eroded out of kimberlite pipes into the surrounding land. The standard ones are garnets, chromites, and ilmenites. One can spend years searching for indicators and tracing them back to the pipes that are their source。 however, 90 percent of kimberlite pipes found this way are barren of diamonds, and the rest are usually too sparse to mine. In the 1970’s the process of locating profitable pipes was refined by focusing on the subtle differences between the chemical signatures of indicator minerals found in diamondrich pipes as opposed to those found in barren pipes. For example, G10 garnets, a type of garnet typically found in diamondrich pipes, are lower in calcium and higher in chrome than garnets from barren pipes. Geochemists John Gurney showed that garnets with this position were formed only in the diamondstability field。 more monly found versions came from elsewhere in the mantle. Gurney also found that though ilmenites did not form in the diamondstability field, there was a link useful for prospectors: when the iron in ilmenite was highly oxidized, its source pipe rarely contained any diamonds. He reasoned that iron took on more or less oxygen in response to conditions in the kimberlitic magma itself—mainly in response to heat and the available oxygen. When iron became highly oxidized, so did diamonds。 that is, they vaporized into carbon dioxide.GWD6Q23:The primary purpose of the passage is to A. discuss an objection to Gurney’s theories about the uses of indicator mineralsB. explore the formation of diamonds and the reasons for their scarcityC. analyze the importance of kimberlite pipes in the formation of diamondsD. define the characteristics of indicator minerals under differing conditionsE. explain a method of determining whether kimberlite pipes are likely to contain diamondsGWD6Q24:Each of the following is mentioned in the passage as a difference between G10 garnet and other versions of garnet EXCEPT A. level of oxidationB. monness of occurrenceC. chemical signatureD. place of formationE. appearance in conjunction with diamondsGWD6Q25:The passage suggests that the presence of G10 garnet in a kimberlite pipe indicates that A. the pipe in which the garnet is found has a 90% chance of containing diamondsB. the levels of calcium and chrome in the pipe are conducive to diamond formationC. the pipe passed through a diamondstability field and thus may contain diamondsD. any diamonds the pipe contains would not have e from the diamondstability fieldE. the pipe’s temperature was so high that it oxidized any diamonds the pipe might have contained GWD6Q26:According to the passage, Gurney refined the use of ilmenites in prospecting for diamonds in which of the following ways?A. He found that ilmenites are brought up from the mantle by kimberlite pipes and erode out into the surrounding land in greater quantities than diamonds.B. He found that since ilmenites do not form in the diamondstability field, their presence indicates the absence of diamonds.C. He showed that highly oxidized iron content in ilmenite