It can be inferred from the passage that calci
问题详情
It can be inferred from the passage that calcium carbonate shells______
A．are not as susceptible to deterioration as rocks
B．are less common in sediments formed during an ice age
C．are found only in areas that were once covered by land ice
D．contain radioactive material that can be used to determine a sediment’s isotopic composition
E．reflect the isotopic composition of the water at the time the shells were formed请帮忙给出正确答案和分析，谢谢！
参考答案
正确答案：E
解析：Eisthebestanswer.Lines29-33ofthepassagestatethatthecalciumcarbonateshellsofmarineorganismsareconstructedwith“oxygenatomsdrawnfromthesurroundingocean.”Thiswatercontainsvaryingproportionsofoxygen16andoxygen18and,accordingtothepassage,“becomesprogressivelyenrichedinoxygen18”withtheonsetofaniceage(lines19-27).Theauthorstatesthat“Thedegreeofenrichmentcanbedeterminedbyanalyzingoceansediments…composedofcalciumcarbonateshellsofmarineorganisms(lines27-31)”.Thus,itcanbeinferredthattheshellsofmarineorganismswouldreflecttheisotopiccompositionofthesurroundingoceanwateratthetimewhentheshellswereformed.
