I stabbed the needle for the injection.

The Riemann sum is a method for approximately calculating the integral of a function.

His performance is generally good.

He followed the footprints left on the snow.

He was appointed as the chief executive officer of the company.

He is an expert in primatology and is engaged in the study of gorilla behavior.

Cytogenetics is a science that studies the structure and function of chromosomes and genes.

He is an expert in nuclear physics.

He is an expert in fluid mechanics.

My father is an expert in otolaryngology.