would you like to come to my birthday party next Sunday?I 'd love to,_ i can't

would you like to come to my birthday party next Sunday?I 'd love to,_ i can't
A and
B because
C so
D but
NOW the air in our hometown is__ than it was before ,and we must do something for that.
A much better
B more worse
C more better
D much worse
These problems are really hard___
Let me help you___ them
A to deal with with
B to do with with
C dealing with for
D doing with for