This math problem is really difficult.

He is suffering from long hours of work.

A boy was playing soccer in the park.

He blames himself for anything and everything.

He showed disapproval of my proposal.

I arranged to meet him at dusk.

My toxicology textbook is very difficult to understand.

How long did you wait?

I was surprised to find a bedbug in the futon.

Japan became an independent state in 1945.