He is majoring in petrology at university.

This cigarette contains carcinogens.

I used binoculars to observe birds in the mountains.

It is said that this substance has a high carcinogenicity.

He was observing the distant birds using binoculars.

This area is rich in peridotite.

This mountain is made of tuff.

Infrared astronomy plays a very important role in the study of the universe.

He didn't know the meaning of 'hanai chimonme'.

I live in the city of Montgomery.