----Are you satisfied with what he did? ----No. It couldn’t have been _____.
The local government announced that only when the fire was under control ________ to return to their homes.
He left home without saying a word, and _______ worries many people and is to be found out.
He came all the way to China for learning it better _______ for making money.
Evidence gained from observation and experiment is often used to _______ a scientific theory.
_______ be sent to work there?