'at', 'on', 'in' 的用法及分別

Prepositions of Time: at, on, and in
We use at to designate specific times.
The train is due at 12:15 p.m.

We use on to designate days and dates.
My brother is coming on Monday.
We're having a party on the Fourth of July.

We use in for nonspecific times during a day, a month, a season, or a year.
She likes to jog in the morning.
It's too cold in winter to run outside.
He started the job in 1971.
He's going to quit in August.

Prepositions of Place: at, on, and in
We use at for specific addresses.
Grammar English lives at 55 Boretz Road in Durham.

We use on to designate names of streets, avenues, etc.
Her house is on Boretz Road.

And we use in for the names of land-areas (towns, counties, states, countries, and continents).
She lives in Durham.
Durham is in Windham County.
Windham County is in Connecticut.

Prepositions of Location: in, at, and on
and No Preposition
IN
(the) bed*
the bedroom
the car
(the) class*
the library*
school*
AT
class*
home
the library*
the office
school*
work
ON
the bed*
the ceiling
the floor
the horse
the plane
the train
NO PREPOSITION
downstairs
downtown
inside
outside
upstairs
uptown

* You may sometimes use different prepositions for these locations.