Prepositions are very important in English. They often tell you how

Prepositions are very important in English. They often tell you how everything happened, when, why.
The three sentences below all have the same preposition missing.
Choose the correct preposition.
I don't enjoy travelling ____ car or boat.
I took the wrong coat ______ mistake. T
he lesson will end ______ 6 o'clock.
on
in
at
by