3.Scientist：More than 1，000 large asteroids regularly cross the Earth's path.Even though the probabil-ity of one colliding with the Earth is extremely slight，we should do whatever we can to reduce that probability since any such collision would be catastrophic.The best way to avoid such a disaster is to deflect the asteroids.The only known way of deflecting asteroids is by hitting them with nuclear weapons that would be stored in space stations.
The scientist's claims are structured so as to lead to which of the following conclusions?
(A)Nuclear technology is the only technology that can plausibly be used to prevent natural catastrophes.
(B)Nuclear weapons should be deployed in space.
(C)No catastrophe has yet been caused by the collision of an asteroid with the Earth.转自:考试网 - [Examw.Com]
(D)The 1，000 large asteroids that cross the Earth's path pose only an extremely slight risk of colliding with the Earth.
(E)There is currently no acceptable use to which nuclear weapons can be put，aside from pro-tecting the Earth from asteroids.
4.It has long been thought that high levels of the hor-mone testosterone contribute to the onset of heart disease in men.However，this view cannot be correct，since men who have heart disease typically show significantly lower levels of testosterone than do men who have not had heart disease.
The argument above assumes which of the following?
(A)Many men who have never had heart disease have unusually low levels of testosterone.
(B)Having heart disease does not significantly lower the level of testosterone in men.
(C)Levels of hormones other than testosterone significantly affect the likelihood that a man will develop heart disease.
(D)Heart disease and lowered testosterone levels in men are the effects of a single common cause.
(E)High levels of testosterone have never been thought to contribute to a serious disease other than heart disease.
5.People who engage in scuba diving are healthier，on average，than people who do not engage in this activity.Therefore，scuba diving tends to promote improved health.
The argument is most vulnerable to criticism on the grounds that it
(A)presupposes that everyone who takes up scuba diving does so solely for health reasons
(B)leads to a further and falsifiable conclusion that no one can achieve good health without engaging in scuba diving
(C)fails to point out that a small number of people are seriously injured in scuba diving accidents each year
(D)treats a precondition for improving one's health as though it were something that by itself could ensure good health
(E)overlooks the possibility that people generally do not take up scuba diving unless they are in good health
