[求助]LSAT 24-1-24

hoechst

24. Each December 31 in Country Q, a tally is made of the country's total available coal supplies-that is, the total amount of coal that has been mined throughout the country but not consumed. In 1991 that amount was considerably lower than it had been in 1990. Furthermore, Country Q has not imported or exported coal since 1970.
If the statements above are true, which one of the following must also be true on the basis of them?
(A) In Country Q, more coal was mined in 1990 than was mined in 1991.
(B) In Country Q, the amount of coal consumed in 1991 was greater than the amount of coal mined in 1991.
(C) In Country Q, the amount of coal consumed in 1990 was greater than the amount of coal consumed in 1991.
(D) In Country Q, the amount of coal consumed in 1991 was greater than the amount of coal consumed in 1990.
(E) In Country Q, more coal was consumed during the first half of 1991 than was consumed during the first half of 1990.

答案是B想不明白

mindfree

The 1991 number should have included the leftover from 1990, because leftover from 1990 is also the amount mined not consumed at the beginning of 1991. So 1990 leftover + 1991 net <1990 leftover ==> 1991 net is negative, meaning consumption is more than production in 1991.