The captain used the speaking tube to communicate with the crew.

I had a delicious tube steak for dinner.

Cathode ray tubes were commonly used in old television sets.

I carefully placed the solution into the test tube.

The thermionic tube is an electronic device that uses the flow of electrons in a vacuum to amplify signals.

The x-ray tube is used to generate x-rays for medical imaging.

She was born through the use of in vitro fertilization, making her a test-tube baby.