This problem occurs at a high frequency.

This building is very high.

It is difficult to predict the occurrence of earthquakes.

When the earthquake occurred, we evacuated immediately.

Can you answer this question?

How tall is this building?

He is an expert in embryology, studying the developmental processes of many kinds of organisms.

The process of embryogenesis is very complex, with continuous cell division and differentiation.

No problem, I will do that job.

That proposal is completely unthinkable.