There are too many choices, I'm confused about which one to choose.

He is my brother-in-arms, and we have overcome many difficulties together.

The cargo ship has arrived at the port.

There is a precedent for this issue.

The study of chromosomes is an important part of cytology.

They occupied the city.

He loves diving and goes to the sea every weekend.

He loves to dive into the sea.

The previous visitor is already using the room, so please wait a moment.

He succeeded in staining the cells.