If you_____this experiment you will understand the theory better

deo, Under the Dome, has rapidly pushed the public______ about air pollution and encouraged people to join in efforts to make a difference.

The charity sale our school organizes every year has taught us much. _______ we would never have learned it in class.

He insisted that he from heart trouble, but I didn’t think so.[ ]

This camera is of good quality. If it ______ break down within the first year, we would replace it with a new one.