I am always monitoring his movements.

Mr. Sudo is my best friend.

Calculating the trajectory is difficult.

He is an expert in ethology.

He is an excellent arranger, and has produced many musical works.

Polar bears live in extremely cold areas.

He is good at playing Beethoven's variations.

We went on a trip using the expressway.

He drew a circle using geometric construction.

We participated in the project with Yo.