推理题中常涉及到时间对比，搞定如何时间对比推理题?在这种推理中，一般有两个形成对比的时间段，它们所具有的特征一般相反。当题干问一个时间段的特征时，只要将与之相反的时间段的特征否定掉就可以了。

　　例一：

　　Basic to any understanding of Canada in the 20 years after the Second World War is the country’s impressive population growth….

　　…It appeared that Canada was once more falling in step with the trend toward smaller families that had occurred all through the Western world since the time of the Industrial Revolution.

　　…

　　It can be inferred from the passage that before the Industrial Revolution

　　(A)families were larger.

　　(B)population statistics were unreliable.

　　(C)the population grew steadily.

　　(D)economic conditions were bad.

　　工业革命之后与工业革命之前两个时间形成对比。既然工业革命之后西方世界的家庭变小了，那么工业革命之前的家庭一定比较大。因此(A)为正确答案。

　　例二：

　　Accustomed though we are to speaking of the films made before 1927 as “silent”， the film has never been， in the full sense of the word， silent. From the very beginning， music was regarded as an indispensable accompaniment; when the Lumiere films were shown at the first public film exhibition in the United States in February 1896， they were accompanied by piano improvisations on popular tunes. At first， the music played bore no special relationship to the films; an accompaniment of any kind was sufficient. Within a very short time， however， the incongruity of playing lively music to a solemn film became apparent， and film pianists began to take some care in matching their pieces to the mood of the film.

　　What can be inferred from the passage about the majority of films made after 1927?

　　(A) They were truly “silent.”

　　(B) They were accompanied by symphonic orchestras.

　　(C) They incorporated the sound of the actors’ voices.

　　(D) They corresponded to specific musical compositions.

　　1927年前后形成对比。既然1927年以前的电影只有音乐而没有配音，那么1927年之后的电影一定有。所以(C)为正确答案。

　　例三：

　　“…The nineteenth century brought with it a burst of new discoveries and inventions that revolutionized the candle industry and made lighting available to all. In the early-to-mid-nineteenth century， a process was developed to refine tallow (fat from animals )with alkali and sulfuric acid. The result was a product called stearin. Stearin is harder and burns longer than unrefined tallow. This breakthrough meant that it was possible to make tallow candles that would not produce the usual smoke and rancid odor. Stearins were also derived from palm oils， so vegetable waxes as well as animal fats could be used to make candles …”

　　Which of the following can be inferred from paragraph 1 about candles before the nineteenth century?

　　?They did not smoke when they were burned.

　　?They produced a pleasant odor as they burned.

　　?They were not available to all.

　　?They contained sulfuric acid.

　　问题：关于19世纪以前的蜡烛，从第一段可以推出下列哪一点?

　　这道题的题干中有“19世纪以前”这一时间，由此可见它属于“时间对比推理”思路。原文首句指出：“…19世纪带来了大量新发现和发明，使蜡烛业发生了革命性的变化，所有人都能用蜡烛照明。” 根据“时间对比推理”思路，由于19世纪以前的情况与19世纪形成对比，而19世纪所有人能用蜡烛照明，那么在19世纪之前，并非所有人都能用上蜡烛。第三个选项 “They were not available to all”表达了这一意思，为正确答案。