Although recent years have seen substantial reductions in noxious pollutants from individual motor vehicles, the number of such vehicles has been steadily increasing. Consequently, more than 100 cities in the United States still have levels of carbon monoxide, particulate matter, and ozone (generated by photochemical reactions with hydrocarbons from vehicle exhaust) that exceed legally established limits. There is a growing realization that the only effective way to achieve further reduction in vehicle emissions -- short of a massive shift away from the private automobile -- is to replace conventional diesel fuel and gasoline with cleaner-burning fuels such as compressed natural gas, liquefied petroleum gas, ethanol, or methanol.
All of these alternatives are carbon-based fuels whose molecules are smaller and simpler than those of gasoline. These molecules burn more cleanly than gasoline, in part because they have fewer, if any, carbon-car-bon bonds and the hydrocarbons t
A. It is substantially less expensive than ethanol.
B. It could be provided to consumers through the existing motor fuel distribution system.
C. It has a higher energy content than other alternative fuels.
D. Its use would reduce the vehicle emissions drastically.
| Disneyland, Knott’s Berry Farm, Magic
Mountain, the State Fair, amusement park…all of these are great family
destinations, yet the cost of the admission ticket alone can put a severe crimp
in the family budget. Once at the park, children are so tempted by the wide
array of food and gift choices that a day intended for family fun can sometimes
turn into an unpleasant nag lest. While it is a parent’s job to say "no" at
appropriate times, saying "no" during a special day intended for family
togetherness can definitely diminish the fun for both adult and child. When our children were in early elementary school, we came up with a plan that took the "yes" and "no" spending decision out of our hands, and placed it into theirs. We were off to Disneyland, and during previous visits our son would badger us for a treat each time w A. He was hesitant to spend his own money. B. He managed to buy things at every corner. C. He was happy and free with his money. D. He used up his money quickly and asked for money again. [多选题] BIM技术在项目哪些阶段的成本控制中能发挥作用()。
A.决策阶段 B.设计阶段 C.施工阶段 D.竣工阶段 E.运维阶段 [单项选择]Passage Two
Questions 29 to 31 are based on the passage you have just heard. A. They do routine work and speak a few languages. B. They see the world and earn a lot of money. C. They look pretty and look after passengers. D. They see the world and do routine work. 我来回答: 提交
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