－ What does the sign over there read － “No person ________ smoke or carry a lighted cigarette, cigar or pipe in this area”

1_____there is no rain,farming is difficult or impossible

1_____education is the instruction that occurs when the instructor and students are separated by distance or time,or both

I had no ______of who I was or what I was going to be.

一Whom would you like to be your assistant，Jack or David？ 一If I had to choose，David would be__________choice.

Duty is an act or a course of action that people __________you to take by social customs, law or religion.

It is generally considered unwise to give a child___( )_____ he or she wants.

My camera can be _____ to take pictures in cloudy or sunny conditions. ( )

Scientists say it may be five or six years _____ this medicine is tested on human beings.

It will be a relief over the death of a friend or a relative if the friend or relative dies from ______.

—We have to stop talking here. Listen, _____!—Hurry up, or we’ll be late.

______no air or water, there would be no life in the world.