TPO22-2 The Allende Meteorite 阿伦德陨星
本文是TPO天文学类文章中较难的一篇，更偏科技，而不止科普。尽管如此，抓住段中考点及逻辑关系，题目也不难解决。我们就从分析下面的句子中寻找“取胜之道”吧!
朗读下列的句子，比背单词、做题的收获大!
1. Sometime after midnight on February 8,1969, a large, bright meteor enteredEarth's atmosphere and broke into thousands of pieces, plummeted to the ground, and scattered over an area 50 miles long and 10 miles wide in the state of Chihuahua in Mexico. (篇章开头句，交代背景;注意一系列动作;阐述特点的细碎信息成为排除题的出题点。)
2. The first meteorite from this fall was found in the village of Pueblito de Allende. Altogether, roughly two tons of meteorite fragments were recovered, all of which bear the name Allende for the location of the first discovery.(句式简洁;推理题出处。)
3. When broken open, Allende stones are revealed to contain an assortment of small, distinctive objects, spherical or irregular in shape and embedded in a darkgray matrix (binding material), which were once constituents of the solarnebula—the interstellar cloud of gas and dust out of which our solar system was formed.(句子简化题出处：划出主干后找到后面一系列修饰成分修饰的主体。)
4. A few chondrules contain grains that survived the melting event, so these enigmatic chondrules must have formed when compact masses of nebular dust were fused at high temperatures—approaching 1,700 degrees Celsius—and then cooled before these surviving grains could melt.(事实信息题出处：因果逻辑关系。)
5. The same minerals that occur in refractory inclusions are believed to be the earliest-formed substances to have condensed out of the solar nebula. However,studies of the textures of inclusions reveal that the order in which the minerals appeared in the inclusions varies from inclusion to inclusion, and often does not match the the oretical condensation sequence for those metals.(句间出现转折，否定事实信息题答案出处，与本句观点相反。)
6. Atone time it was thought that these matrix grains might be pristine nebular dust, the sort of stuff from which chondrules and inclusions were made.However, detailed studies of the chondrite matrix suggest that much of it, too, has been formed by condensationor melting in the nebula, although minute amounts of surviving interstellar dust are mixed with the processed materials.(有一个观点的转折成为事实信息题出题点，把握作者最终阐述的观点。)
7. To compare the compositions of a meteorite and the Sun, it is necessary that we use ratios of elements rather than simply the abundances of atoms. After all, the Sun has many moreatoms of any element, say iron, than does a meteorite specimen, but the ratios of iron to silicon in the two kinds of matter might be comparable. The compositional similarity is striking. The major difference is that Allende is depleted in the most volatile elements, like hydrogen, carbon, oxygen, nitrogen, and the noblegases, relative to the Sun.(段落中比较相同点和不同点是重要考点之一，本篇设置修辞目的、事实信息两道题目。)
8. Since practically all the solar system's mass resides in the Sun, this similarity in chemistry means that chondrites have average solar system composition, except for the most volatile elements; they are truly lumps of nebular matter, probably similar in composition to the matter from which planets were assembled.(段末结论句，因果逻辑关系;事实信息题出处，需将此句仔细分析。)
亲们不要忘记关注下方“一起过托福”的微信公众号，最新、最热的留学备考信息每天都有推送喔~，走过路过千万不要错过!
微信扫描下方二维码，第一时间知晓托福考试真题预测及解析，还有北美留学最新动态喔~(微信号：toefl120)!