The patrol boat is patrolling the sea area.

He likes to read Chinese poetry.

The guard is guarding the gate.

This box is filled with plenty of buffering material to protect the delicate glass products.

I read this weekly magazine every week.

Every morning, it's my daily routine to read the daily newspaper while drinking coffee.

When he gets angry, his veins that bulge when he is angry become visible.

He is inclined to sentimentalism.

The indefinite article is a basic part of English grammar.

He measured the humidity using a psychrometer.