This rock is gabbro.

He is majoring in petrology at university.

The students lined up in response to the teacher's instructions.

He cleaned the bowl of the pipe thoroughly.

This cigarette contains carcinogens.

I used binoculars to observe birds in the mountains.

It is said that this substance has a high carcinogenicity.

Gon's educational policy is very strict.

Scientists are advancing research on nuclear fusion.

His name is a proper noun, known all over the world.