There is not a single cloud in the sky.

He checked his answers against the correct ones.

In view of the facts, his actions are understandable.

The moon quietly illuminates the sea.

That disease is caused by a mutation.

The air in this room is fresh.

The altitude of this airplane is 10,000 meters.

What will you use this empty box for?

I enjoyed a picnic under the clear sky.

He wants to make a car that can fly in the air.