The U.S.A. made a lot of excuses in an attempt to make war on Iran. However, its ____ purpose lay in the plentiful oil there. A. incredible B. fundamental C. flexible D. identical
The research is so designed that once _____ nothing can be done to change it.
If _____ carefully, the experiment will be successful.
He is a man of few words, and seldom speaks until _____ to.
They kept trying _____ they must have known it was hopeless.
There are five pairs, but I'm at a loss which _____ to buy.