【每日逻辑练习第二季】【1-1】

jiajiajudy

CR 一天不做就有罪恶感了

1.    Carl is clearly an incompetent detective. He has
solved a smaller percentage of the cases assigned to
him in the last 3 years—only 1 out of 25—than any
other detective on the police force.
Premise: he solved a smaller percentage of the cases than others in last 3 years
Conclusion: Carl is clearly an incompetent detective
Flow:  low rate of success because the cases are very difficult than others
A
2. Background: Although fullerenes--spherical molecules made entirely of carbon--were first found in the laboratory, they have since been found in nature, formed in fissures of the rare mineral shungite. Premise: Since laboratory synthesis of fullerenes requires distinctive conditions of temperature and pressure, conclusion: this discovery should give geologists a test case for evaluating hypotheses about the state of the Earth's crust at the time these naturally occurring fullerenes were formed.
B

3. Economist: BG: On average, the emergency treatment for an elderly person for injuries resulting from a fall costs $11,000. Premise: A new therapeutic program can significantly reduce an elderly person's chances of falling. Counter premise: Though obviously desirable for many reasons, this treatment program will cost $12,500 and conclusion: thus cannot be justified.
C

4.BG: The prairie vole, a small North American grassland rodent, breeds year-round, and a group of voles living together consists primarily of an extended family, often including two or more litters. Premise: Voles commonly live in large groups from late autumn through winter; counter premise: from spring through early autumn, however, most voles live in far smaller groups. Conclusion: The seasonal variation in group size can probably be explained by a seasonal variation in mortality among young voles.
E

5. Premise: A popular beach has long had a dolphin feeding program in which fish are given to dolphins several times a day; many dolphins get as much as half of their food each day there. Counter premise: Although dolphins that first benefit from the program as adults are healthy and long-lived, conclusion: their offspring have a lower life expectancy than offspring of dolphins that feed exclusively in the wild.

Which of the following, if true, most helps to explain the lower life expectancy of offspring of dolphins feeding at the beach compared to other young dolphins?
E