【问】 because of，on account of和for这三个介词都可以表示原因，不知它们之间有什么区别?
 【答】 介词because of用于表示引起事件发生的直接原因：
 1. Because of their high vitamin and low calorie content，mushrooms are included in cer-tain diets. (TOEFL)
 由于蘑菇含有极高的维生素和极低的热量，所以有一些食物里含有蘑菇。
 2. ____advantageous geographical location，Jersey City became commercially importantearly in its history.
 A. Because of its B. That its
 C. Its D. Since its(TOEFL，80.3)
 3. There were 200，000 gallons of water on the set that could have helped put out the fire，but 70 firemen could not reach it because of the heat. (The Guardian)
 摄影场有20万加仑水，本可以用来帮助灭火，但是70名消防队员因为高温而无法接近它。(卫报)
 on account of与because of具有同样的意义，但是它仅用在正式语体中：
 1. On account of his youth，he was not allowed to take the senior course. (Hill)
 由于他太小，不允许他选高级课程。
 2. On account of his wide experience，he was made chairman. (CGEL)
 由于他具有广泛的经验，他当选了主席。
 for除了能表示because of这一含义之外，还常常用于表示心理原因(动机)：
 1. He was rewarded for his bravery. (LDAE)
 他因勇敢而获奖。
 2. Don't be angry with me for not having written. (Yeats)
 不要因为我没有写信而生我的气。
 3. He left an hour early for fear of missing the train. (DAI)
 由于怕赶不上火车，他早走了一个小时。
 4. He ran away for fear of being caught by the enemy. (Mis)
 由于害怕被敌人抓住，他逃跑了。
 5. I hid the money for fear of what my parents would say.
 我把钱藏起来了，以免我父母说些什么。
 6. He hung down his head for shame. (McMordie)
 他羞悔得垂下了头。
 7. We jumped for joy. (Mis)
 我们高兴得跳了起来。