Why does Mars have such a thin atmosphere? Scientists have long hypothesized that chemical reactions among water, carbon dioxide, and rock turned the original thick Martian atmosphere into carbonate mineral solids. The carbonates were never recycled back into carbon dioxide gas because Mars, being so small, cooled quickly and its volcanoes---which might have released dissolved gases back into the atmosphere---stopped erupting. However, so far only a single small area of carbonate rock has been found on Mars, and this outcrop probably formed in warm subsurface waters. Moreover, the carbonate theory offers no explanation for why Mars has so little nitrogen or noble gases. Escape provides a better answer. The atmosphere did not get locked away as rock, it dissipated into space.
Based on the passage, the author would agree that if the hypothesis mentioned in the highlighted sentence was true, then which of the following would also probably be true?
Volcanoes on Mars are important to the issue addressed by the passage primarily for which reason?
Globally, the combination of reforestation and afforestation activities could reduce atmosphere CO2 concentrations by as much as 30 parts per million (ppm) this century. However, this potential mitigation is limited by many factors. One is the vulnerability of forests to increased disturbances, including those caused by pathogens, droughts, fires, and storms. For example, the mountain pine beetle is projected to convert 374,000 square kilometers (km2) of pine forest from a small net carbon sink to a large carbon source in Alberta alone, liberating 1 billion tons of CO2 into the atmosphere. Climate change is another factor that could limit the potential for carbon sequestration in forests. The mountain pine beetle in Alberta is thriving in part because of warmer minimum temperatures in the winter and warmer and drier summers. A third potential limitation is landowner behavior in private-sector forestry, including decisions on what species to plant and how intensely to manage forests. Private forestry competes economically with agriculture, urban development, and other land uses. Landowner decisions will therefore dictate the success of some climate policy efforts.
The primary purpose of the passage is to
The author mention "agriculture" in order to
The passage suggests which of the following about Alberta?
Gender socialization theory argues that learned gender stereotypes influence workers` preferences for particular job attributes: men acquire the breadwinner role while women acquire the homemaker role, and workers therefore prefer job attributes related to these gender roles. Earlier research provides some support for this theory. From the 1930s to the mid-1980s, studies documented significant differences between men`s and women`s job attribute preferences: men preferred earnings, advancement, and job security more than women did, whereas women valued coworker relationships and flexible work hours compatible with family responsibilities. However, recent research has cast doubt on this explanation. Heckert found that although women rated job conditions such as flexible work hours higher than did men, there were no significant gender differences in workers` attitudes toward pay or factors related to promotions.
The author suggests which of the following about Heckert`s research?
It can be inferred from the passage that "earlier research" different from Heckert`s research in that the "earlier research"
Until the French Revolution of 1789 and the Napoleonic Wars at the turn of the eighteenth and nineteenth centuries, chemistry in European universities had generally led a marginal existence. Most university teachers of chemistry were there to provide a service for students of medicine and pharmacy. The number of significant research chemists could be reckoned as a few dozen internationally, and, with the partial exceptions of France and Germany, it made little or no sense to talk about national chemical communities. There were distinguished professors, for example, Hermann Boerhaave in the Netherlands at the beginning of the eighteenth century and Joseph Black in Edinburgh at the end of that century. For the most part, however, university chairs in chemistry were few and had little prestige. Chemistry, unlike medicine, did not constitute a profession in its own right.

There were industries that were based on the application of chemistry, but most of these depended on a traditional mixture of ingredients: entrepreneurial skill, recipes that had been found to work, and the tactile expertise of the practitioner rather than the theoretical insights of the academic chemist. Chemists were of course engaged in practical applications of their science. In the Royal Academy of Sciences in Paris, members of the Academy functioned in part as a scientific civil service and bent their energies to solving problems of water quality, street lighting, sewage disposal, and more. The French Enlightenment`s great Encyclopedia was directly concerned with learning from the practice of artisans, and thereby both enriching theoretical understanding and improving craft and industrial practice. Joseph Black advised the masters of ironworks, Swedish chemists became expert mineralogists and consultants to the mining industry, and military chemists worked in many nations on the improvement of gunpowder. But in every one of these cases, chemistry was a tool, a servant not a master, in the view of patrons and the public if not in the view of the chemists themselves.

Chemistry lacked prestige, and chemists often worked in isolation, with little recognition from the wider community of science. Newtonian physics and astronomy were the model sciences for the eighteenth century. Many shared the great eighteenth-century philosopher Immanuel Kant`s view that chemistry was incapable of becoming a science and could never be more than a kind of systematic natural history, an organized compilation of facts derived from experiment and observation. Chemistry---socially, professionally, economically, and scientifically---was a poor relative in the hierarchical family of the sciences.
The author mentions Hermann Boerhaave as a
Which of the following statements about chemistry in eighteenth century universities can be inferred from the passage?
According to the second paragraph, chemistry tended to be regarded as
Regarding the chemists who were "engaged in practical applications of their science", it can be inferred from the passage that in some cases they
The Musical Dice Game was published under the name of Mozart, the renowned composer, shortly after his death in 1791. The Dice Game consists of 176 numbered musical fragments, each three beats long, and instructions on how to compose short waltzes by ordering selected fragments according to the throw of the dice. Some music historians contend that the Dice Game was not authored by Mozart, correctly asserting that Mozart did not need to rely on such a system to compose music, but their view that Mozart was too creative to have used such a device is inappropriately based on a nineteenth-century Romantic concept of composers. In fact, Mozart loved puzzles and games, and equivalent fragments exist in his own handwriting. Moreover, countless music professionals contemporary with Mozart explored and promulgated new compositional methods. Indeed, nearly every prominent composer of Mozart`s day created a dice game. The triviality of the music produced by the Dice Game, however, strongly suggests that someone other than Mozart authored the game, basing it loosely on fragments discarded by Mozart.
The author mentions which of the following as evidence tending to undermine the claim that Mozart was the author of The Musical Dice Game?
Which of the following statements about Mozart and The musical Dice Game is most consistent with the view expressed by the author of the passage?
The author of the passage suggests that the view of the "music historians" concerning Mozart`s authorship of the game published under his name is based on
Availability and management of water greatly influenced human settlement in the Maya Lowlands, and much of Mayan social innovation was centered on storing excess water for times of need. In northern Yucatan the permanent water table is sufficiently shallow that it can be accessed by natural wells known as cenotes. However, over much of the Maya Lowlands, the water table is too deep to have been available to the Maya. In response, they constructed artificial reservoirs to trap runoff. For example, Gallopin estimates that the reservoirs at Tikal (an ancient Mayan city) could have provided for the domestic needs of about 9,600 people for a period of 6 to 18 months. Even with elaborate water capture and management systems, the Maya were greatly dependent upon adequate rainfall over much of their empire and were thus susceptible to frequent or prolonged droughts that approached or exceeded the capacity of their reservoirs. In fact, evidence of droughts in the region based on studies of lake and shallow ocean sediments has led many researchers to suspect that climate was responsible for the Classic Maya collapse.


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