|
1.In response to viral infection, the immune systems of mice typically produce antibodies that destroy the virus by binding to proteins on its surface. Mice infected with a herpesvirus generally develop keratitis, a degenerative disease affecting part of the eye. Since proteins on the surface of cells in this part of the eye closely resemble those on the herpesvirus surface, scientists hypothesize that these cases of keratitis are caused by antibodies to herpesvirus. Which of the following, if true, gives the greatest additional support to the scientists’ hypothesis? A. Other types of virus have surface proteins that closely resemble proteins found in various organs of mice.
B. There are mice that are unable to form antibodies in response to herpes infections, and these mice contract herpes at roughly the same rate as other mice.C. Mice that are infected with a herpesvirus but do not develop keratitis produce as many antibodies as infected mice that do develop keratitis. D. There are mice that are unable to form antibodies in response to herpes infections, and these mice survive these infections without ever developing keratitis. E. Mice that have never been infected with a herpesvirus can sometimes develop keratitis. 请问大家答案是选D么 异因异果加强？ 2 Plantings of cotton bioengineered to produce its own insecticide against bollworms, a major cause of crop failure, sustained little bollworm damage until this year. This year the plantings are being seriously damaged by bollworms. Bollworms, however, are not necessarily developing resistance to the cotton’s insecticide. Bollworms breed on corn, and last year more corn than usual was planted throughout cotton-growing regions. So it is likely that the cotton is simply being overwhelmed by corn-bred bollworms. In evaluating the argument, which of the following would it be most useful to establish?
A. Whether corn could be bioengineered to produce the insecticideB. Whether plantings of cotton that does not produce the insecticide are suffering unusually extensive damage from bollworms this year C. Whether other crops that have been bioengineered to produce their own insecticide successfully resist the pests against which the insecticide was to protect them D. Whether plantings of bioengineered cotton are frequently damaged by insect pests other than bollworms E. Whether there are insecticides that can be used against bollworms that have developed resistance to the insecticide produced by the bioengineered cotton 此题是否选C 多谢大家帮忙看一下哈~
[此贴子已经被作者于2008-5-4 23:20:17编辑过] | 
京公网安备11010202008513号 京ICP证101109号 京ICP备12012021号
发表于 2008-5-4 23:08:00
