Our friend has been here for some months now, and he must know exactly the effect those ice storms have.

But we do know the effect these woods have on humans.

You know - right or wrong - the effect we have on each other.

But no one knows the effect these drugs are having.

No one else knew the devastating effect the sun had on him.

I cannot know the effect it will have on him.

I know the devastating effect on the world if it is done wrong.

Much less do we know the effect of anything on it.

I know the effect a good lawyer can make on a jury.

No one knows the true effect this is having on our health.