Sufficient caution is necessary when handling radioactive materials.

Cosmic background radiation is considered evidence of the Big Bang.

Radioactive elements are produced in nature and scientific experiments.

There is a state-of-the-art incubator in my laboratory.

This old battery is no longer usable.

I mixed the pancake batter with my new whisk.

He is well-versed in the use of hidden weapons.

He analyzed the light of the stars using a new spectroscope.

He spoke to the people at the assembly using a loudspeaker.

If you press this switch, the lights will turn on.