1)Children gifts ( ) Christmas and ( ) their birthday

1)Children gifts ( ) Christmas and ( ) their birthday
A on;on
B at;on
C in;in
D in;on
2)I worked on the problem ( ) a long time and I worked it out ( ) myself ( ) last
A for;by;at
B in;with;on
C on;by;in
D for;for;at the
3)They suddenly returned ( ) a rainy night
A on
B at
C in
D during
4)Ann moved ( )HangZou ( ) September,1992
A ;in
B to;in
C to;on
D in;in
5)The train is starting ( ) five minutes
A in
B at
C for
D still