重点讲解：
1. die of 死于；
例句：Some of them died of thirst in the desert.
他们中有些人在沙漠中渴死了。
2. because of 因为；由于；
例句：He eats only bland food because of his ulcer.
他患溃疡，只能吃无刺激性的食物。
3. find out （尤指特意通过努力）发现，找出，查明；
例句：He was at pains to find out the truth.
他尽力了解事实真相。
4. as well as 除…之外；也；还；
例句：This is true of management as well as of workers.
很多管理人员和工人都是这种情况。
5. specialize in 专门从事；专门经营；专门研究；专攻；
例句：This shop specializes in chocolates.
这个商店专门出售巧克力。