People have planted a lot of trees and grass in order to ____ wind and sand in the desert.
--- Remember, Dad, Thomas Edison got bad grades in school, too. --- Stay in your room until you’ve _____ the electric lamp.A invented B discovered C made D imagined
There isn’t much time_____ . shall we go now? A leaving B to leave C being left D left
____ he came back home that we knew what had happened .
It was the training _____ he had as a young man _____ made him such a good engineer.
It was _____ he said _____ disappointed me at that time.