Because of Einstein’s Theory of Relativity, scientists never again regarded the world .
He doesn’t have the habit of planning his travel expense, so he won’t know what to do _______ the money runs out.
The news _______ is spreading around the airport is _______ a heavy storm is coming.
It is known to all that a proper amount of exercise _______ to good health.
-I can’t believe that you _______ that old trick.-Yes, I was stupid enough.
Don’t worry. You _______ have the tickets for the games.