—Waiter, ______ ?—Sure. Here’s your bill.
After the class was over, the student apologized _______ the teacher ______ his coming late.
_____________ well prepared you are, you still need a lot of luck in mountain climbing.
I think only when he attends college _______________ more independent of his parents.
Using his hybrid rice, farmers are producing harvests ________________ before.
The situation is getting worse. We must __________ the trouble _____________.