gwd-29-40

ly365

Q40:

Mice that have been given morphine are very likely to develop blood poisoning because bacteria that normally reside in the intestine typically respond to morphine by migrating into the bloodstream.  However, when mice are given both morphine and the new drug naltrexone, blood poisoning is much less frequent, although it does still occur.  These results provide support for researchers’ prediction that naltrexone will turn out to be toxic to certain types of bacteria.

 

Which of the following, if discovered to be true, would most seriously weaken the support for the researchers’ prediction?

 

1. After being administered to mice, naltrexone does not pass from the bloodstream into the intestine.
2. Naltrexone inhibits morphine from triggering the migration of intestinal bacteria into the bloodstream.
3. Mice that have been given naltrexone but not morphine have no greater risk of developing blood poisoning than do mice that have not been given either substance.
4. The increased risk of blood poisoning is not the only harmful effect on mice of being given morphine.

Conditions other than the presence of intestinal bacteria in the bloodstream can cause blood poisoning in mice.

答案B，我选E 请教

kallyli

B is the best answer to weaken the support of the researchers' prediction that naltrexone will turn out to be toxic to certain types of bacteria, for the decrease frequent of blood poisoning is not because of the inhibits of bacteria themselves(toxic to them) but of the migration of intestinal bacteria into the bloodstream.
while in E, there is even no mention of naltrexone which is the central idea of the researchers' prediction.

mbz

 agree with kallyli, good job

mymengming

以下是引用kallyli在2006-7-11 18:31:00的发言：
B is the best answer to weaken the support of the researchers' prediction that naltrexone will turn out to be toxic to certain types of bacteria, for the decrease frequent of blood poisoning is not because of the inhibits of bacteria themselves(toxic to them) but of the migration of intestinal bacteria into the bloodstream.
while in E, there is even no mention of naltrexone which is the central idea of the researchers' prediction.

支持

yangxuemei0111

还是有点似懂非懂

chang2301

請問C錯在哪?

C說blood poisoning的機會:N but no M=No N and M

可以解釋成N單獨存在時也不會造成blood poisoning所以不會toxic to certain types of bacteria嗎?

請幫忙喔

娜娜仁

??

gonghao

Not toxic but hibit

davidli8888

My vote is B. The basic reasoning is as follows:

if the blood poisoning is caused by other reason (as described in B), then the researchers’ prediction becomes groundless (weakened).

Choice B gives another way by which the blood poisoning does not happen, ie. if the blood poisoning takes place when the bacteria migrate from intestine into bloodstream, then the new drug functioning by inhibiting the migration into bloodstream rather than poisoning some bacteria - the researchers' prediction.

[此贴子已经被作者于2006-12-2 23:36:51编辑过]

lxzjojo

up