The shaft of this building is very narrow.

He is an expert in ethology, and his research is highly regarded worldwide.

I used an optical microscope for an experiment at school.

Demography is an important tool for understanding various aspects of society.

He looked like a god.

He suddenly stiffened and fell down.

He was greatly excited about the new project.

This season, the cherry blossoms are blooming beautifully.

The efficacy of this medicine is very high.

He was enclosed in his own thoughts.