Can't work out the difference between:
(1) There are a lot of things to do here.
(2) There a lot of things to be done here.
Is it about modality? Possibility vs. necessity?
(3) This is a book to read.
(4) This is the book to be read.
Does (3) mean 'worth reading' and (4) 'that must be read'?
(5) This box is too heavy to lift.
Is it possible to say:
(6) This box is too heavy to be lifted?