Sex chromosomes play an important role in determining the sex of an organism.

Let's solve this problem with unity in diversity.

He was struggling to understand the concept of a hypercube.

He is undergoing training for extravehicular activity.

He engaged in an extravehicular activity from the spaceship.

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

I have been to Outer Mongolia.

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

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

This sentence contains kanji not approved for regular use.