It is important to maintain your body temperature at a suitable level.

It is important to maintain backward compatibility with software that was written to run on the former system.

New York City has long been unusual because of its sheer size.

It is easy to make a man one's friend, but hard to keep him so.

It is hard to maintain one's reputation.

Try to keep in touch with me, just in case.

To survive, the polar bear must keep its body at the right temperature and store enough energy to last between meals that could be a few days or a few months apart.

It's difficult to balance a ball on your nose.

She tried to keep her presence of mind.

She really keeps her youthfulness.

He keeps his youth by jogging.

You must not keep in touch with him.

Japan maintains friendly relations with the United States.

Natural dyes keep a more beautiful color over the years than artificial dyes.

Homeroom teachers should make every effort to keep in touch with their students.

For appearances sake, I went.

What do you do to stay in shape?

Before we try to move up to the next level, I think we need to focus on keeping what we have.

I keep in touch with my parents in my hometown by phone.

I tried to keep my teacher at a distance.