Choose the correct preposition to coplete the sentences.1

Choose the correct preposition to coplete the sentences.1.Do not forget to check (at/in) two hours before your flight.2.if you do not throw these scrissors (away/up) , you will be in trouble with the security check.3.We'll have to get rid (of/off) these old newspapers.Nobody needs them.4.Hurry up! Your flight is (on/in) time .5.I like to sit (by/in) the windiw , but i got a place (by/in) the aisle