We learned about the protection of the main sea.

I am majoring in oceanography.

He hired a lawyer to protect his interests.

There is a bad relationship between him and me.

Due to the new coronavirus, we had to undergo a two-week quarantine.

He was hospitalized for a stomach ulcer.

When spring comes, the forest begins to come into leaf.

When spring comes, the trees in the forest come into leaf.

He sensed her extreme hatred.

Their relationship is exactly like cats and dogs.