The book is bought by me.(I buy the book.)是我买书（或书被我买）
The food was eaten by the tiger.(The tiger ate the food.)
大多数是这种形式：sth be done by sb/sth.
另外：
——My car doesn't work.I have to have my car repaired.(这里：sb have sth done,也表示被动,即我的车需要被修理了.)
——My car doesn't work.It needs repairing(感觉mending更好.).(这里sth need doing也有被动的味道.)
——你应该知道make sb do吧?
example:He always makes me smile.可改为：I am always made to smile(by him).(不太典型.但能说明区别.)
就这么差不多了哈.
