I have a lot of work to be done.我有许多工作要完成.

I have a lot of work to be done.我有很多工作要（让别人）做.
I have a lot of work to do.我有很多工作要做.这是非谓语结构中动词不定式主动表被动,胆动作发出者仍是主语 I
在一种情况下两者意思一样,既：There is a lot of work to do/to be done.（没有出现具体动作发出者的情况下）