He is training to strengthen the tightening of his muscles.

He tightened his fists in tension.

I am reading the Old Testament.

This sentence is written in a contracted form.

This fabric contracts when it absorbs water.

This document has been shortened for abbreviation.

This sentence is too long, please abbreviate it.

He is a lawyer with a deep understanding of the covenant.

Using punctuation marks correctly is important for understanding sentences.

My friend came from Gansu province.