You will not succeed ______ you work harder.
My son want a pet rabbit for long, but I have no time to buy ______ for him.
We have two rooms _______, but I can’t decide ________.
—I didn’t know this is a one-way street, sir.—______. Please show your driving license.
The work is too difficult for Mr. Zhu to finish in a week. He needs ______ days.
Peter doesn’t tell me when he _______. I’ll telephone you as soon as he ______.