This shirt is made of chemical fiber.

My child attends a supplementary school every Saturday.

This blade is very sharp.

He is suffering from combat stress reaction.

Essential amino acids cannot be produced by the human body, so they need to be obtained from the diet.

Essential amino acids, which the human body cannot produce on its own, need to be obtained from the diet.

Essential amino acids are necessary to be taken from our diet because our body cannot produce them on its own.

He understands the meaning of the proverb 'Teaching is half learning', which means that teaching leads to one's own learning.

Minoru is my best friend.

The concept of chemical equivalent is essential for understanding chemical reactions.