We suddenly saw the bus about to leave and had to run _____ to catch it.

There is ____ as a free dinner in this world, as the saying goes, “No pains, no gains.”

The earth could be younger and took more than three times longer to form than _______ thought, according to a new study.

It is very ___that the factory will have to close because the economic crisis . 

You should know _______to spend all your money on those impractical fancy goods.