看过前辈的回答了,但是觉得B是不是可以认为是他因造成butterfly caterpillars 的死亡呢,应该可以认为是一种weaken吧。请路过NN指教!
以下是引用考试专业户在2006-3-17 16:49:00的发言:
一种基因种植的玉米会自然产生一种防虫体,这种防虫体遍布玉米的上下,包括其花粉。玉米的花粉因被风吹送,所以经常会落在通常种在玉米边上的MILKWEED上。一种蝴蝶的毛毛虫主要吃MILKWEED的叶子。在实验中发现,当这些毛毛虫吃了有那种玉米花粉的叶子就会死。所以,种这种玉米就会有之前没想到的危害这种蝴蝶的后果。 (翻译得好象怪怪的,不好意思,凑合着看吧) Which of the following, if true, most seriously weakens the argument? (找一个理由来支持种这个玉米对这个蝴蝶无害) - Per unit of volume, the natural insecticide produced by the genetically modified maize plants is less toxic to insects than are many commercial insecticides commonly used on maize plants.第一,即使没有其它的杀虫剂厉害,但是也足够杀死毛毛虫了。第二,毛毛虫不是在玉米身上,是在玉米边的MILKWEED上。两个理由支持这个选项为无关选项。
- Standard weed-control practices that have been used by farmers for decades have largely eliminated milkweed plants from certain areas where monarch-butterfly caterpillars were once common. MILKWEED多不多不关紧要,题目中是说如果玉米边上有MILKWEED的话,那么它上面的毛毛虫就可能被毒死。要的答案是说毛毛虫不会被毒死。明显这个选项无关。
- The experiments showed that the caterpillars were not harmed by contact with the pollen from the genetically modified plants unless they ingested it.说了半天就是因为毛毛虫会吃那个叶子,而那个叶子上有花粉。如果它不吃那整个前提都变了。这个不止是无关,完全是在改题。
- The maize-eating insects that the natural insecticide protects against do not feed on the pollen of the maize plant.吃玉米的害虫不吃花粉可以吃其它的,这个和在milkweed上的毛毛虫没丝毫关系。无关。
- Airborne maize pollen tends to collect on the middle leaves of milkweed plants and monarch caterpillars feed only on the plant’s tender upper leaves. 也就是说毛毛虫吃的叶子是不会有花粉的,正确。
|