My father underwent surgery for kidney stones.

He is collecting stamps.

He is an international student from America.

He is a first-class chef.

A fermion is one of the fundamental constituents of matter.

We need to measure the strength of this electric current.

Due to the influence of ocean currents, the distribution of marine life can change.

Many types of fish inhabit this river basin.

This electrical appliance requires a direct current power supply.

This river and that river confluence here.