ChaseDream

标题: 求助:大全sectiong20-12 [打印本页]

作者: windy_ccl    时间: 2007-3-21 23:42
标题: 求助:大全sectiong20-12

    

10.   Last
year the worldwide paper industry used over twice as much fresh pulp (pulp made
directly from raw plant fibers) as recycled pulp (pulp made from wastepaper). A
paper-industry analyst has projected that by 2010 the industry will use at
least as much recycled pulp annually as it does fresh pulp, while using a
greater quantity of fresh pulp than it did last year.


    

If the information above is correct and
the analyst’s projections prove to be accurate, which of the following
projections must also be accurate?


    

(A) In 2010 the paper industry
will use at least twice as much recycled pulp as it did last years.

        


    

(B) In 2010 the
paper industry will use at least twice as much total pulp as it did last year.


    

(C) In 2010 the
paper industry will produce more paper from a given amount of pulp than it did
last year.


    

(D) As compared with last year, in
2010 the paper industry will make more paper that contains only recycled pulp.
A


    

(E) As compared
with last year, in 2010 the paper industry will make less paper that contains
only fresh pulp.


不懂哦,答案是A



作者: gonghao    时间: 2007-3-22 11:30

A正确的

去年:新鲜纸浆(X1)=2*(循环纸浆Y1)

2010年:新鲜纸浆(X2)=(循环纸浆Y2)

X2>X1

X2=X1>Y1

x2>y1(即A)


作者: dingxiang    时间: 2008-6-9 10:44

gonghao的推理不是A的形式啊

A的形式是 Y2> 2 Y1

由原文的条件:

去年:新鲜纸浆(X1)=2*(循环纸浆Y1)

2010年:新鲜纸浆(X2)=(循环纸浆Y2)

X2>X1

可以推得, Y2=X2 > X1 =2 Y1

所以 得到 Y2 > 2Y1






欢迎光临 ChaseDream (https://forum.chasedream.com/) Powered by Discuz! X3.3