Hi all,
Thanks for your comments.
"You should complete the work in on time"
Is the preposition required in the above sentence?
No, it's wrong. Both 'in' and 'on' are prepositions.
You can complete the work in time or complete the work on
time, but not both. (Same with 'submit').
You can hand the work in on time, (or hand in the work on time)
because "hand in" is a separable phrasal verb. 'In' belongs to "hand in", and 'on' belongs to the prepositional phrase "on time".
or
"You should complete the work on time" is OK?
Yes.