At
1 The film starts at 10 o'clock
2 He often works at night
3 The question was discussed at the meeting
4 They entered at the front door
5 She doesn't have to shout at me
In
1 They waited in silence
2 She retired in August
3 He died in four months
4 The little girl looked at me in horror
5 Her life was in danger
On
1 He came on his bike
2 He was born on August 1st
3 She had a black suit on
4 They will be here on Friday
5 The window opens on the street
1 I met her last Friday
2 We will discuss the matter next time
3 We got along well during the trip
4 We arrived while they were watching TV
5 They played until it got dark