His efforts are worthy of praise.

His efforts were praised by everyone.

In Sanskrit phonology, the concept of triphthong is important.

The spring breed of silkworms has started making cocoons.

He descended from the airplane using a parachute.

Every year, many fish gather in this river for spawning.

Frogs spawn when spring comes.

The sourness of this lemon adds a good accent to the dish.

His headache was so severe that he could hardly move.

When I heard the details of the incident, I felt appalling.