13. Choose the correct variant

Nobody in the family believes Carl has paid the heating bill, ____ ?

a) do they
b) has he
c) doesn't he
d) won't they
e) did they

14. Choose the correct variant

. . .... one do you like better -the one on the left or the one on the right?

a) Which
b) Where
c) What
d) Who's
e) What kind