His career is at its prime.

I got caught in the rain on the way.

He used skywriting for his proposal.

Astronautics is a field of study related to the exploration of space and the design of spacecraft.

He is majoring in astronautics.

He was surprised to see the column of water.

I have been to Sinuiju.

He spent a lot of time in jail.

He is an expert in astrophysics, and his research is highly valued around the world.

He is in the midst of studying for the exam.