You will succeed in the end ________ you give up halfway.
—What a mistake! —Yes. I ________ his doing it another way, but without success.
—Simon is watching TV. —He's watching TV? He's ________to be cleaning his room.
—Can I use your telephone?—________.
It's not enough. We need ________ more than that.
The terrible weather ________ our difficulty in building the road.