在2014年5月11日的托福閱讀考試中有這樣一道題：如何判斷地質(zhì)年齡。針對(duì)這道托?？碱}，出國(guó)留學(xué)網(wǎng)(www.liuxue86.com)小編來(lái)為大家普及一下關(guān)于地質(zhì)年齡的背景知識(shí)，這樣有助于考生在面對(duì)這類題目時(shí)方便作答。小編在此提醒大家：天文主題文章的詞匯專業(yè)性較強(qiáng)，需要提前對(duì)相關(guān)專題的TPO文章的生詞熟悉，盡量減少生詞恐懼帶來(lái)的內(nèi)耗。
托福閱讀真題再現(xiàn)：
版本1:
文章先講太陽(yáng)系里的東西都有相同的起源。先是說(shuō)所有的東西是在一起的，然后說(shuō)地球由于地表的水、火山活動(dòng)和一個(gè)什么過(guò)程使得地球連最古老的石頭都沒有了。所以只能測(cè)定月球的隕石的成分了，結(jié)論是月球的表面和隕石的時(shí)間都是46億年。因?yàn)樵虑虮砻鏇]有地球的這些活動(dòng)，所以可以測(cè)定。
后面又說(shuō)宇宙的星系都在不斷地拉開距離，通過(guò)星系的紅移可以確定距離還有速度，發(fā)現(xiàn)宇宙一直在膨脹。發(fā)現(xiàn)宇宙在137億年前是一個(gè)點(diǎn)。然后就有了宇宙大爆炸。
版本2： 講地球和宇宙年齡的測(cè)量。先說(shuō)太陽(yáng)系大部分物質(zhì)是同一時(shí)間形成的，然后說(shuō)地球年齡難是因?yàn)檎l(shuí)腐蝕。接著引入一種物質(zhì)，可以通過(guò)同位素測(cè)年齡。結(jié)果是和月球上的最古老的石頭近似。然后說(shuō)宇宙在膨脹，大爆炸。通過(guò)紅移測(cè)年齡。
版本3： 天文類， 某種地球上的物質(zhì)和月球上最古老的物質(zhì)證明他。都始于自4.6million年前，于是證明太陽(yáng)系的年齡是4.6 Million years. 另外還有種通過(guò)判斷各星球一種wavelength的大小推斷出他們?cè)诙嗌倌昵岸际菑膫€(gè)spot發(fā)展出來(lái)，于是判斷了big bang的時(shí)間。
托福閱讀相關(guān)詞匯：
origin 起源
meteorite 隕石
galaxy 星系
expansion 膨脹
red shift 紅移
wavelength 波長(zhǎng)
解析：
天文主題文章的詞匯專業(yè)性較強(qiáng)，需要提前對(duì)相關(guān)專題的TPO文章的生詞熟悉，盡量減少生詞恐懼帶來(lái)的內(nèi)耗。另外，出現(xiàn)天文理論的文章，結(jié)構(gòu)通常都會(huì)比較清晰，但要著重識(shí)別對(duì)理論內(nèi)容的態(tài)度傾向。
托福閱讀相關(guān)背景：
a.Big Bang
The Big Bang theory is the prevailing cosmological model for the early development of the universe. According to the theory, the Big Bang occurred approximately 13.82 billion years ago, which is thus considered the age of the universe. At this time, the universe was in an extremely hot and dense state and was expanding rapidly. After the initial expansion, the universe cooled sufficiently to allow the formation of subatomic particles, including protons, neutrons, and electrons. Though simple atomic nuclei formed within the first three minutes after the Big Bang, thousands of years passed before the first electrically neutral atoms formed. The majority of atoms that were produced by the Big Bang are hydrogen, along with helium and traces of lithium. Giant clouds of these primordial elements later coalesced through gravity to form stars and galaxies, and the heavier elements were synthesized either within stars or during supernovae.
b.Accelerating universe
The accelerating universe is the observation that the universe appears to be expanding at an increasing rate. In formal terms, this means that the cosmic scale factor has a positive second derivative,[1] so that the velocity at which a distant galaxy is receding from us should be continuously increasing with time.[2] In 1998, observations of type Ia supernovae also suggested that the expansion of the universe has been accelerating[3][4] since around redshift of z~0.5.[5] The 2006 Shaw Prize in Astronomy and the 2011 Nobel Prize in Physics were both awarded to Saul Perlmutter, Brian P. Schmidt, and Adam G. Riess, who in 1998 as leaders of the Supernova Cosmology Project (Perlmutter) and the High-Z Supernova Search Team (Schmidt and Riess) discovered the accelerating expansion of the Universe through observations of distant ("High-Z") supernovae.[6][7]
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