The external shell of a crab is very hard.

He is strengthening his muscles by doing shoulder abduction exercises.

The rear-facing camera is broken, so I need to buy a new smartphone.

He was fishing outside of the boat.

He was told by the doctor that supination of his wrist is difficult.

We are planning to travel outside of the prefecture next week.

He was struggling to perform external rotation of the shoulder.

In Sanskrit phonology, bilabial sounds play an important role.

In female anatomy, the labia majora is a part of the external genitalia.

This univalve has beautiful colors, doesn't it?