distribute,deliver,dictate,demonstrate为什么无被动语态

以上动词均是及物动词,有被动语态.
例如：Leaflets were distributed to passers-by.传单被散发给路人.
The goods will be delivered within a week. 货物将一周之内传送.
A letter has been dictated to the secretary.一封信已经口述给秘书.
How to use the machine has been demonstrated by the manager. 怎样使用这台机器已经被经理证明了.
老师祝你学习进步!
望采纳,多谢!^_^

这些词我都见过用在被动语态的句式中，你从哪儿被告知不行或没有的？