Preposizioni di tempo

_____ summer
1. in
2. on
3. at
_____ Monday
1. in
2. on
3. at
_____ the afternoon
1. in
2. on
3. at
_____ night
1. in
2. on
3. at
_____ lunchtime
1. in
2. on
3. at
_____ 29th November 1971
1. in
2. on
3. at
_____ 1981
1. in
2. on
3. at
_____ half past six
1. in
2. on
3. at
_____ Christmas day
1. in
2. on
3. at
_____ Christmas time
1. in
2. on
3. at