The external intercostal muscle plays an important role in respiration.

The external anal sphincter plays a crucial role in helping us control defecation.

The external urethral sphincter is an important muscle for controlling the excretion of urine.

I went to see the beautiful scenery of Sotogahama.

I have been to Outer Mongolia.

Coitus interruptus is one method of contraception, but it is not completely reliable.

There are many introduced species of plants living in this park.

He is the type of person who understands ten from hearing one.

He is exactly in the state of 'A frog in a well does not know the vast ocean.'

He spoke of his big dreams, saying, 'How can a sparrow understand the ambitions of a swan?'