YOU WON‟T HAVE A SEAT UNLESS YOU BOOK IN ADVANCE. A. YOU CAN‟T HAV...

20. You won‟t have a seat unless you book in advance.

A. You can‟t have a seat although you book in advance.

B. You will have a seat if you don‟t book in advance.

C. You didn‟t have a seat because you didn‟t book in advance.

D. You won‟t have a seat if you don‟t book in advance.