He received the letter challenging him to a duel and began preparing for the duel.

He is doing special exercises to strengthen his sagittal muscles.

He pointed to the location of the styloid process with his finger.

His shaft fracture has completely healed.

The leaves of this plant are arranged in a pinnate manner.

I received a summons from the court yesterday.

Mammals can maintain a constant body temperature.

Primates are a group of mammals that include humans.

Crustaceans are a type of marine life, including crabs and shrimps.

Insects are an important part of the natural world.