Why do the people decide ______ these days —Because there’s not much to do.

Can you guess if they ______ to play basketball with us –I think they’ll come if they _____ free.

In order to _________ a good learning atmosphere, our teacher made strict rules for us at the beginning of this term.

____is known to us all is that the old worker, ____life was hard in the past, still works hard in his seventies.

下列各组词语中，有一个错别字的一组是（ ）