You’d better put things back______. Otherwise, it will be difficult to find them.

 Working abroad for many years, he has made a big _______ and started a company of his own.

One of my classmates accidentally ____ he had cheated in the last examination, or he wouldn’t have got so high a mark.

. --- Do you have any trouble explaining the sentence?         ---No, _____

 We recently did a simple experiment, which happens to ________ how children's knowledge of what a hero is like determines their behaviour.