He won the mahjong game by self-drawing the winning tile.

He chose suicide.

Facing a desperate situation, he chose to commit suicide.

He made a self-oath to achieve his goals.

He took an oath to himself to succeed.

This hermit crab can perform autotomy when it senses danger, allowing it to escape from enemies.

This self-propelled lawnmower is very convenient.

She takes good care of her natural nails and never neglects them.

He likes to take a walk in the park at dusk.

A row vector is one of the basic concepts in linear algebra.