今天注意到一个规律， 如果提干讨论过去（如现象解释）， 则选项应该是关于过去； 或者提干讨论将来（如PREDICTION， SOLUTION， PROPOSAL， SOLUTION 等等）， 则选项应该是也关于将来。 不知道大家有什么看法和体会， 希望NN交流！
现举一例 OG202，选项B 用现在完成时只表明过去的情况，而问题是说以后如何如何， 所以错。
202.
Gortland
has long been narrowly self-sufficient in both grain and meat. However, as per
capita income in Gortland has risen toward the world average, per capita
consumption of meat has also risen toward the world average, and it takes
several pounds of grain to produce one pound of meat. Therefore, since per
capita income continues to rise, whereas domestic grain production will not
increase, Gortland will soon have to import either grain or meat or both.
Which of the following is an assumption on which the argument depends?
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(A)The total acreage devoted to grain production in Gortland will not decrease
substantially.
(B)The population of Gortland has remained relatively constant during the
country’s years of growing prosperity.
(C)The per capita consumption of meat in Gortland is roughly the same across all
income levels.
(D)In Gortland, neither meat nor grain is subject to government price controls.
(E)People in Gortland who increase their consumption of meat will not radically
decrease their consumption of grain. | 
