_____________ you have done might do harm to other people.

The students are _______ to ride the public bicyclesto Mount Tianlong for a spring outing.

Whenever Mary hears something interesting, she can’t keep it to and wants to share it with me.

Everything from greeting to eating can be an opportunity to do the wrong thing which not only embarrasses yourself, but ____ your host. [ ]

He has read many books on history, so it’s _________ for him to answer these questions.