1. GMAT CAT CR*10/23
(1)The organizers of the tomorrow's outdoor concert announced that it will go on tomorrow on schedule unless bad weather is forecast or too few advance tickets are sold. (2)If the concert is canceled,refunds will be made to ticket holders.(3)Since some ticket holders have already been issued refunds even though more than enough advance tickets were sold,it must be the case that bad weather is forecast.
Which of the following is an error of reasoning contained in the argument?
a)It proceeds as if a condition,which by itself is enough to guarantee a certain result is the only condition under which that result would occur.
b)It bases a conclusion that is known to require two conditions on evidence that bears on only one of those conditions.
c)It explains one event as being caused by another event,even though both events must actually have been caused by some thired,unidentified event.
d)It treats evidence for the absence of one condition under which a circumstance would occur as conclusive evidence that that circumstance will not occur.
e)Evidence given to support the conclusion actuallly undermines it.
key A
先说说我的思路，
由(1)：根据在前进上课学到的逻辑 not A unless B(A doesn't occurs unless B occurs)推出 A-->B 得到：
outdoor concert not go on schedule(即cancel) ---> bad weather forecast OR too few advance tickets sold
由(2)：outdoor concert cancel--->refunds
由(3)： refunds AND many advance tickets sold--->bad weather forecast
照理说,由(1)(2)并不能推出(3),可是5个选项又一个都对不上,着急.
2-3 GMAT 97.5 S1/8-9
In the industrialized nations,the last century has witnessed a shortening of the average workday from twelve hours or longer to less than eight hours.Mindful of this enormous increase in lesure time over the past century,many people assume that the same trend has obtained throughout history,and that,therefore,prehistoric humans must have labored incessantly for their very survival.
We cannot,of course,directly test this assumption.However,a study of primitive peoples of today suggests a different conclusion.The Mbuti of central Africa,for instance,spend only a few hours each day in hunting,gathering,and tending to other economic necessities.The rest of their time is apent as they choose.The implication is that the short workday is not peculiar to industralized societies.Rather,both the extended workday of 1880 and the shorter workday of today are products of different stages of the continuing process of industrialization.
2.Which of the following inferences about industralization is best supported by the passage above?
a)People in advanced industrialized societies have more leisure time than those in nonindustrialized societies.
b)An average workday of twelve hours or more is peculiar to economies in the early stages of industrialization.
c)Industrialization involes a trade-off between tedious,monotonous jobs and the benefits of increased leisure.
d)It is likely that the extended workday of an industrializing country will eventually be shortened.
e)As industrialization progresses,people tend to look for self-fulfillment in leisure rather than work.
key D
my choice C
3. Which of the following,if true,would most greatly strengthen the argument made in the passage above?
a)In recent decades,the economy of the Mbuti has been markedly affected by the encroachmeng of modern humans.
b)The life-style of the Mbuti is similar to that of prehistoric humans.
c)The Mbuti have no words in their language to express the distinction between work activities and leisure activities.
d)The workday of a European peasant in medieval times averaged between eleven and fifteen hours.
e)The members of the Shaklik tribe in central Asia have an average workday of ten to twelve hours.
key Bffice ffice" /> | 
