The book has been translated into thirty languagessince it ______ on the market in 1973.

Li Ming likes playing ____basketball, but his sister likes playing___piano.

The young man insisted that he _____ nothing wrong and _____ free.

How many students are going to the GreatWall— ____.

_________ this phenomenon, we must take some measures to deal with it; otherwise, it will _________ great losses in the future.