说理在各种写作中式必不可少的，而因果又是说理中不可或缺的。下面汇总了 TPO 中常用的表示原因的一些表达，防止大家一个 because 一用到底。来看下面的整理。

　　result from

　　In general, it is believed that these two extinctions resulted from drastic environmental changes that followed meteorite impacts or massive volcanic eruptions. [TPO 15-2-1]

　　总体来说，这两次灭绝被认为是陨石撞击或者大规模的火山爆发导致的剧烈的环境变化造成的。

　　In general, it is believed that X results from A.

　　result primarily or mainly or largely from

　　The growth of independent guilds was furthered by the fact that surplus was not a result of domestic craft production but resulted primarily from international trading;

　　独立行会不断增加，是因为剩余价值的产生并非由于国内生产，而是主要来自于国际间的贸易活动。

　　X is not a result of A but results primarily from B.

　　one of the most likely causes for

　　Evidence points to hunting by humans and habitat destruction as the likely causes for the current mass extinction. [TPO 15-2-3]

　　但有证据指出，人类狩猎以及破坏栖息地很可能是当前大规模物种灭绝的原因。

　　Sb. points to A and B as the likely causes of X.

　　the explanation may be that

　　The explanation may be that the terrestrial planets were once much larger and richer in these materials but eventually lost them because of these bodies’ relative closeness to the Sun, which meant that their temperatures were relatively high. [TPO 16-3-6]

　　有一种解释认为，类地行星曾经体积更大并且物质构成上更为丰富多样，但因为它们距太阳较近致使温度相对较高而最终失去这些物质。

　　the most obvious reason for sb to do sth is that

　　Few have directly questioned what might lead a teacher to want to become reflective. Apparently, the most obvious reason for teachers to work toward reflective practice is that teacher educators think it is a good thing. [TPO 9-2-6]

　　很少人直接质疑什么可能让一个教师想变成反思型教师。显然，使教师朝着反思行为努力的最直接的原因是师资培训者认为这是一件很好的事情。

　　Few have directly questioned what might lead sb. to do X. Apparently, the most obvious reason for sb. to do X is that A.

　　partly due to

　　This has been so since ancient times, partly due to the geology of the area, which is mostly limestone and sandstone, with few deposits of metallic ore and other useful materials. Ancient demands for obsidian (a black volcanic rock useful for making mirrors and tools) led to trade with Armenia to the north, while jade for cutting tools was brought from Turkistan, and the precious stone lapis lazuli was imported from Afghanistan. [TPO 16-1-1]