22.If we know more about _______causes the problem, we may take measures before it is _______late.
Our teacher looked here and there on our playground ________ looking for something.
________to the man’s timely coming,the________boy was saved.
—Mr Black,what about my application? —Oh,I regret________you that it hasn’t been successful.
The experts advise _______ our army _______ modern weapons.
If I ruled the world, I would _______ the world ______ everything that is bad.