You ________ touch the chemical, or you ________ get burnt.
.He seemed to be looking for the words ____ he could express his idea.
.A modern city has been set up in ____ was a wasteland ten years ago.
To make members of a team perform better, the trainer first of all has to know their ____ and weaknesses.
In the new century, we still should _____ primary importance to the development of economy.
I remember _____ this used to be a quiet village.