A (a)   is a medical procedure where a small sample of tissue is removed for examination.

The (a)   refers to the zone of Earth where life exists, including the air, land, and water.

Poor nutrition can be (a)   to a person, leaving them lacking energy and strength.

A (a)   is a microscopic organism, such as a bacterium or virus.

The doctor used a defibrillator, successfully (a)   the patient after their heart stopped.

(a)   is a mutually beneficial relationship between two different species.

Only ideas that are practical and capable of working are considered (a)   .

The (a)   of a person refers to their physical and mental energy or vigor.

The sunset painted the sky (a)   in hues of orange, pink, and purple.