编辑：share 来源： 美联出国考试 发布时间：2016-07-27
TOEFL 例句 This impact released an enormous amount of energy, excavating a crater about twice as large as the lunar crater Tycho. ——TPO-4: Meteorite Impact and Dinosaur Extinction
ex-=out，如“expanding”（展开的，扩大的）（TPO-20: Westward Migration）
cav=hollow，如“cavity”（洞；穴）（TPO-12: Water in the Desert）
-ate*动词后缀，如“cooperate”（合作）（TPO-13: Types of Social Groups）
TOEFL 例句 To make a twig more effective for digging out termites, for example, a chimp may first strip it of its leaves.——TOEFL 2004年8月题
Passage Excerpt: “This impact released an enormous amount of energy, excavating a crater about twice as large as the lunar crater Tycho. The explosion lifted about 100 trillion tons of dust into the atmosphere, as can be determined by measuring the thickness of the sediment layer formed when this dust settled to the surface. Such a quantity of material would have blocked the sunlight completely from reaching the surface, plunging Earth into a period of cold and darkness that lasted at least several months. The explosion is also calculated to have produced vast quantities of nitric acid and melted rock that sprayed out over much of Earth, starting widespread fires that must have consumed most terrestrial forests and grassland. Presumably, those environmental disasters could have been responsible for the mass extinction, including the death of the dinosaurs.”
Official Model Exam: Meteorite Impact and Dinosaur Extinction
The word “excavating” in the passage is closest in meaning to___.
A. digging out B. extending C. destroying D. covering up
Passage Excerpt: “What could cause such high rates of extinction? There are several hypotheses, including warming or cooling of Earth, changes in seasonal fluctuations or ocean currents, and changing positions of the continents. Biological hypotheses include ecological changes brought about by the evolution of cooperation between insects and flowering plants or of bottom-feeding predators in the oceans. Some of the proposed mechanisms required a very brief period during which all extinctions suddenly took place; other mechanisms would be more likely to have taken place more gradually, over an extended period, or at different times on different continents. Some hypotheses fail to account for simultaneous extinctions on land and in the seas. Each mass extinction may have had a different cause. Evidence points to hunting by humans and habitat destruction as the likely causes for the current mass extinction.”
TPO-15: Mass Extinctions
The word “extended” in the passage is closest in meaning to___.
A.specific B.unlimited C.reasonable D. long