.......Saturday morning
A: at
B: on
C: no preposition
D: in
.... twelve o´clock
A: at
B: in
C: on
D: no preposition
... the evening
A: in
B: no preposition
C: on
D: at
...... this evening
A: on
B: no preposition
C: at
D: in
...... Christmas
A: on
B: in
C: at
D: no preposition
.... yesterday
A: on
B: no preposition
C: in
D: at
..... the future
A: in
B: on
C: no preposition
D: at
...... summer
A: no preposition
B: on
C: in
D: at
..... last summer
A: on
B: at
C: no preposition
D: in
..... my birthday
A: at
B: no preposition
C: on
D: in
.... midnight
A: in
B: at
C: no preposition
D: on
..... New Year´s Day
A: at
B: no preposition
C: in
D: on
.... 1918
A: in
B: at
C: on
D: no preposition
..... the nineties
A: at
B: no preposition
C: in
D: on
.... the nineteenth of March
A: no preposition
B: at
C: on
D: in