He is undergoing training for extravehicular activity.

He is a foreigner, but he can speak Japanese fluently.

This book explains in detail about the use of foreign words.

If you train your external oblique muscles, your waist will become tighter.

He is doing a special exercise to strengthen his abductor digiti minimi.

He is doing special exercises to strengthen his abductor digiti minimi.

I started exercises to strengthen the abductor hallucis muscle.

He is doing special exercises to strengthen his abductor pollicis brevis.

He is doing special exercises to strengthen his abductor pollicis longus.