11-tpo154答案以匹克軟件為準(zhǔn)咨詢小助手223the allende meteorite

1、The Allende Meteorite broke o thousands of pie, plummeted to the ground, and scattered over an area 50 long and 10 he village of wide he se of Chihuahua exico. The meteorite from this fall was found Pueblito de Allende. Altogether, roughly two tons of meteorite fragments were recovered, all of which

2、 bear the name Allende for the location of the discovery.Individual specimens of Allende are covered wi black, glassy crust t formed when their exteriors melted as they were slowed by Earths atmosphere. When broken open, Allende stones are revealed to contain an assortment of small, distinctive obje

3、cts, spherical or irregular in shand embedded in a dark gray matrix (binding material), which were once constituents of the solar nebulatheerslar cloud of gas and dust out of which our solar system was formed. chondrosmeaning seedlu to their appearance as rocks containing tiny seeds. These seeds are

4、 actually chondrules: millimeter-sized melted droplets of silicate material t were cooled o spheres of glass and crystal. A few chondrules contain grains t survived the melting event, so these enigmatic chondrules musve formed when compact masses of nebular dust were fused at high temperatures and t

5、hen cooled before these surviving grains could melt. Study of the textures of chondrules confirms t they cooled rather quickly, imes measured inutes or hours, so the heating events t formed them must temperatures, and huge nebula areas could not sibly e lost heat so fast. Chondrules musve been melte

6、d in small pockets of the nebula spheres remains an enigma.t were able to lose heat raly. The origin of these peculiar glassy Equally plexing constituents of Allende are the refractory inclus: irregular white masses t tend to be larger n chondrules. They are comed of mineralsmon on Earth, all rich i

7、n calcium, aluminum, and titanium, the most refractory (resistant to melting) of the major elements he nebula. The same minerals t occur in refractory inclus are beved to be the earst-formed substan to e condensed out of the solar nebula. However, studies of the textures of inclus reveal t the order

8、 in which the minerals appeared he inclus varies from inclu to inclu, and often does not match Chondrules and inclus in Allende are held together by the chondrite matrix, a mixture of fine-grained, mostly silicate minerals t also includes grains of iron metal and iron sulfide. At one time it was tho

9、ught t these matrix grains might be pristine nebular dust, the sort of sturom which chondrules and inclus were made. However, ed studies of the chondrite matrix suggest t much of it, too, has been formed by condensation or melting he nebula, although minute amounts of surviving erslar dust are mixed

10、 with the prosed materials.All these diverse constituents are aggregated together to form chondritic meteorites, like Allende,te chemical comitions much liket of the Sun. To compare the comitions of a meteorite and theSun, it is nesaryt we use ratios of elements rathern simply the abundanof atoms. A

11、fter all, theSun has many more atoms of any element, say iron,n does a meteorite specimen, but the ratios of iron tosiliconhe two kinds of matter might be comparable. The comitional similarity is striking. The majordifference ist Allende is depletedhe most volatile elements, like hydrogen, carbon, o

12、xygen, nitrogen, and the noble gases, relative to the Sun. These are the elementst tend to form gases even at very lowtemperatures. We might think of chondrites as samples of distilled Sun, a sort of solar sludge from which only gasese been removed. Since practically all the solar systems mass resid

13、eshe Sun, this similarityin chemistry meanst chondritese average solar system comition, except for the most volatileelements; they are truly lumps of nebular matter, probably similar in comition to the matter from which planets were assembled.Paragraph 1: Sometime after midnight on February 8,1969,

14、a large, bright meteor entered Earths atmosphere and broke o thousands of pie, plummeted to the ground, and scattered over an area 50 long and 10 wide he se of Chihuahua exico. The meteorite from this fall was found he village of Pueblito de Allende. Altogether, roughly two tons of meteorite fragmen

15、ts were recovered, all of which bear the name Allende for the location of the discovery.the theoretical condensation sequence for those metals.e been localized. It seems very unlikely t large portions of the nebula were heated to such extremeThe Allende meteorite is classified as a chondrite. Chondr

16、ites take their name from the Greek wordSometime after midnight on February 8,1969, a large, bright meteor entered Earths atmosphere and1.The word locationOsighthe passage is closesteaning toO O Osake sucs place2.Which of the following can be inferred from paragraph 1 about the large meteort entered

17、 Earths atmosphere on February 8, 1969?OIt was almos tenwide.O O OIt was the biggest meteor ever to hit Mexico.It weighed moren two tons.It brokeo moren most meteors do.Paragraph 2: Individual specimens of Allende are covered wi black, glassy crust t formed when their exteriors melted as they were s

18、lowed by Earths atmosphere. When broken open, Allende stones are revealed to contain an assortment of small, distinctive objects, spherical or irregular in sh and embedded in a dark gray matrix (binding material), which were once constituents of the solar nebulathe erslarcloud of gas and dust out of

19、 which our solar system was formed.3.Which of the sentenbelow best expresses the essential informationhe highlighted sentencehepassage? Incorrect choichange the meaning in important ways or leave out essential information.OAllende meteorites were formed when constituents of theerslar cloud of gas an

20、d dust gottrapped inside small, roughly spherical objects and these objects became bound together in a dark gray matrix.OInside Allende meteorites is a dark gray matrixt binds together small spherical or irregularobjects formed from the made.erslar cloud of gas and dust out of which the solar system

21、 wasOOBy breaking open Allende meteorites, scientists were able to find out what the solar nebula was made of.Allende meteorites were filled with material formed almost entirely from dust.erslar gas andParagraph 3: The Allende meteorite is classified as a chondrite. Chondrites take their name from t

22、he Greek word chondrosmeaning seedlu to their appearance as rocks containing tiny seeds. These seeds are actually chondrules: millimeter-sized melted droplets of silicate material t were cooled e formed when compact masses of nebular dust were fused at high temperaturesapproaching 1,700 degrees Cels

23、iusand then cooled before these surviving grains could melt. Study of the textures of chondrules confirms t they cooled rather quickly, imes measured inutes or hours, so the heating events t formed them musve been localized. It seems very unlikely t large portions of the nebula were heated to such e

24、xtreme temperatures, and huge nebula areas could not sibly heat raly. The origin of these peculiar glassy spheres remains an enigma.4.The word alluhe passage is closesteaning toOadditionO modification O resemblance O reference5.The word enigmaticOdangeroushe passage is closesteaning toO O Omysteriou

25、s erestingsurprising6.According to paragraph 3, what does the presence of grains inside some of the chondrules indicate?OThe chondrules were formed of silicate material.O O OThe chondrules were formed at high temperatures and then cooled ra The grains were formed in huge areas of the solar nebulaly.

26、The grains were formed after the chondrules were fused togethero chondrites.enigmatic chondrules muste lost heat so fast. Chondrules musve been melted in small pockets of the nebulat were able to loseo spheres of glass and crystal. A few chondrules contain grains t survived the melting event, so the

27、se masses t tend to be larger n chondrules. They are comed of mineralsmon on Earth, all rich in calcium, aluminum, and titanium, the most refractory (resistant to melting) of the major elements he nebula. The same minerals t occur in refractory inclus are beved to be the earst-formed substan to e co

28、ndensed out of the solar nebula. However, studies of the textures of inclus reveal t the order in which the minerals appeared he inclus varies from inclu to inclu, and often does not match the theoretical condensation sequence for those metals.7.According to paragraph 4, all of the following are tru

29、e about the minerals found in the refractoryincluOOO Os EXCEPT:These minerals are among the most resistant to melting of all the major elements nebula.he solarThese minerals are beved to be some of the nebula.elements toe condensed out of the solarThese minerals are among the least commonly found el

30、ements on Earth.These elements occurhe ordert scientists woulde predicted.Paragraph 5: Chondrules and inclu of fine-grained, mostly silicate minerals s in Allende are held together by the chondrite matrix, a mixture t also includes grains of iron metal and iron sulfide. At one time it was thought t

31、these matrix grains might be pristine nebular dust, the sort of sturom which chondrules and inclus were made. However, ed studies of the chondrite matrix suggest t much of it, too, has been formed by condensation or melting he nebula, although minute amounts of surviving erslar dust are mixed with t

32、he prosed materials.8.The word pristineOpurehe passage is closesteaning toO O Osolid ordinary trapped9.According to paragraph 5, which of the following is indicated by studies of the mixture holding the inclus together?O O O OLarge amounts of this material were formed by condensation or meltinghe ne

33、bula.This material contains more iron and iron sulfiden hreviously been thought.This material is very similar to the material from which the refractory inclus are madeThe grainshis material are made from the same elements as chondrules are.Paragraph 6: All these diverse constituents are aggregated t

34、ogether to form chondritic meteorites, like Allende,te chemical comitions much liket of the Sun. To compare the comitions of ameteorite and the Sun, it is nesaryt we use ratios of elements rathern simply the abundanofatoms. After all, the Sun has many more atoms of any element, say iron, n does a me

35、teorite specimen, but the ratios of iron to siliconhe two kinds of matter might be comparable. The comitional similarity isstriking. The major difference ist Allende is depletedhe most volatile elements, like hydrogen, carbon,oxygen, nitrogen, and the noble gases, relative to the Sun. These are the

36、elementst tend to form gaseseven at very low temperatures. We might think of chondrites as samples of distilled Sun, a sort of solar sludgefrom which only gasese been removed. Since practically all the solar systems mass resideshe Sun,this similarity in chemistry meanst chondritese average solar sys

37、tem comition, except for themost volatile elements; they are truly lumps of nebular matter, probably similar in comition to the matter from which planets were assembled.10. In paragraph 6, why does the author mentiont the Sun has many more atoms of any element, sayiron, n does a meteorite specimen?O

38、To show how difficult it is to compare the comition of a meteorite witht of the SunOO OTo explain why a comparison of the com terms of ratios of elementsitions of a meteorite and of the Sun has to be done inTo identify the most common element in both the Sun and meteorite specimensTo emphasize how m

39、uch larger the Sun isn any meteorite specimen isAccording to paragraph 6, the com Sun primarily inition of chondritic meteorites differs from the comition of theOcontaining nebular matterOcontaining many fewer atoms of ironParagraph 4: Equally plexing constituents of Allende are the refractory inclu

40、s: irregular whiteO Othe relative amount of volatile elements the ratio of iron to silicon11. According to paragraph 6, what is the significance of the similarity in com and the Sun?ition betn chondritesOIt indicates what the matter from which planets were formed was probably like.O O OIt may explai

41、n howthe Sun originally developed.It helps scientists estimate the variationshe chemical comition of different meteors.It suggestst most meteorites may contain largeties of volatile elements. to be larger n chondrules. They are comed of mineralsmon on Earth, all rich in calcium, aluminum, and titani

42、um, the most refractory (resistant to melting) of the major elements he nebula. The same minerals t occur in refractory inclus are beved to be the earst-formed substan to order in which the minerals appeared he inclus varies from inclu to inclu, and often does not match the theoretical condensation

43、sequence for those metals. 12.Look at the four squares t indicate where the following sentence could be added to the passageIt is therefore stilclear if all inclus were formedhe same way.Where would the sentence best fit?13.Directions: Anroductory sentence for a brief summary of the passage is provi

44、ded below. Completethe summary by selecting the THREE answer choit express the most important ideas in thepassage. Some sentendo not belong in the summary because they express ideast are nots.ition ofpresentedhe passage or are minor ideashe passage. This question is worth 2 po Studies of the Allende

45、 meteorite provided information about the comchondritic meteorites and theirO O Osible origin.Answer Choi When Allende entered Earths atmosphere, it broke because they look like glassy, black seeds.O O O O OOo thousands of piecalled chondritesThe mineral content of chondruleggestst they were probabl

46、y formed in isolated regionsof the nebulat remained much hottern the rest.Chondrules are tiny, millimeter-sized drops of silicate materialst probably formed whenlumps of nebular dust were fused at extremely high temperatures and then quickly cooled.Irregularly shd inclus in Allende are comed of mine

47、ralst are resistant to meltingand are beved to be the earst minerals toe condensed out of the nebula.The matrixt holds the chondrules and inclus together in Allende consists mainly ofgrains of nebular dustt were trapped inside the meteor before they could be melted.Except for being depleted in volatile elements, chondritic meteorites are probably very similar incomition to the matter from