The mere presence of us in the past might alter the future.

But the new report shows that the mere presence of condoms does not alter behavior.

Even so, his presence probably would not have altered the outcome.

Mr. Turner also said "the presence of a camera can alter any situation."

What if his presence here had irrevocably altered the timeline?

The presence of one or two strong leaders can alter the course of history.

I rather imagine that my presence here will alter the vote somewhat.'

Your presence may alter the future and harm human history.

The presence of the boni had radically altered the situation.

But the presence of the alien, and the things stored in the alien's cave, altered all the ground rules.