GWD-24-35新疑问,谢谢

arig

The
milk of many mammals contains cannabinoids, substances that are known
to stimulate certain receptors in the brain. To investigate the
function of cannabinoids, researchers injected newborn mice with a
chemical that is known to block cannabinoides from reaching their
receptors in the brain. The injected mice showed far less interest in
feeding than normal newborn mice do. Therefore, cannabinoids probably
function to stimulate the appetite.

A)   Newborn mice do not normally ingest any substance other than their mothers’ milk.

B)   Cannabinoids are the only substances in mammals’ milk that stimulate the appetite.

C)   The mothers of newborn mice do not normally make any effort to encourage their babies to feed.

D)   The mild of mammals would be less nutritious if it did not contain cannabinoids.

E)    The chemical that blocks cannabinoids from stimulating their brain receptors does not independently inhibit the appetite.

E是排除了他因,可是B也排除了他因,为什么B不对呢?

gonghao

would you pls put the question into the argument above.

If it is assumption,B repeated the conclusion does not qualified for the assumption at all.

even though "can~" is one of the substances that has the function to stimulate the appetite,the conclusion will not be weaken since the "can ~" is capable of sitmulating the appetite.

[此贴子已经被作者于2006-10-8 20:43:16编辑过]

arig

sure,make sense,thx!
Even if B + not,the conclusion is still supported but E is not like this.