OG12-49

echine

Certaingeneticallymodifiedstrainsofmaizeproduceapowerfulnaturalinsecticide.Theinsecticideoccursthroughouttheplant,includingitspollen.Maizepollenisdispersedbythewindandfrequentlyblowsontomilkweedplantsthatgrownearmaizefields.Caterpillarsofmonarchbutterfliesfeedexclusivelyonmilkweedleaves.Whenthesecaterpillarsarefedmilkweedleavesdustedwithpollenfrommodifiedmaizeplants,theydie.Therefore,byusinggeneticallymodifiedmaize,farmersputmonarchbutterfliesatrisk.

Whichofthefollowingwoulditbemostusefultodetermineinordertoevaluatetheargument?

(A)Whetherthenaturalinsecticideisaseffectiveagainstmaize-eatinginsectsascommercialinsecticidestypicallyusedonmaizeare

(B)Whetherthepollenofgeneticallymodifiedmaizecontainsasmuchinsecticideasotherpartsoftheseplants

(C)Whethermonarchbutterflycaterpillarsareactivelyfeedingduringthepartofthegrowingseasonwhenmaizeisreleasingpollen

(D)Whetherinsectsthatfeedongeneticallymodifiedmaizeplantsarelikelytobekilledbyinsecticidefromtheplant'spollen

(E)Whetheranymaize-eatinginsectscompetewithmonarchcaterpillarsfortheleavesofmilkweedplantsgrowingnearmaizefields

答案是C 可是我觉得E和C的效果是一样的，有谁可以帮我解释一下两者的区别？

gjyrxqgzj

对E还是有些疑问 如果maize-eating insects把milkweed leaves都吃掉了，monarch caterpillars吃不到milkweed leaves，不受insecticide的影响，不也weaken argument 吗？

gwang5

SDCAR真是好人啊！这么花眼的题目都有爱心去回复！

echine

明白了，insecticide,谢谢！
PS：题目发的太不清晰，对不住大家！

sdcar2010

Certain genetically modified strains of maize produce a powerful natural insecticide. The
insecticide occurs throughout the plant, including its pollen. Maize pollen is dispersed by
the wind and frequently blows onto milkweed plants that grow near maize fields.
Caterpillars of monarch butterflies feed exclusively on milkweed leaves. When these
caterpillars are fed milkweed leaves dusted with pollen from modified maize plants, they
die. Therefore, by using genetically modified maize, farmers put monarch butterflies at
risk.
Which of the following would it be most useful to determine in order to evaluate the
argument?
A. Whether the natural insecticide is as effective against maize-eating insects as
commercial insecticides typically used on maize are
B. Whether the pollen of genetically modified maize contains as much insecticide as
other parts of these plants
C. Whether monarch butterfly caterpillars are actively feeding during the part of the
growing season when maize is releasing pollen
D. Whether insects that feed on genetically modified maize plants are likely to be
killed by insecticide from the plant’s pollen
E. Whether any maize-eating insects compete with monarch caterpillars for the
leaves of milkweed plants growing near maize fields

Why does E matter with regard to the argument? Since the pollen is toxic to insects, all insects eating the pollen, either directly from the maize or the leaves of milkweek will die.