He is a world-renowned zoologist.

It's difficult to understand the principles of electrooptics.

I am majoring in econometrics at university.

Hitori is my best friend.

He is as strong as an ox.

He explained the importance of studying while young, saying 'If you do not study when you are young, it will be difficult to learn when you are old.'

I used an optical microscope for an experiment at school.

Humanities is an academic field that studies human culture and society.

We adjusted our travel schedule according to Mountain Standard Time.

He lives with the spirit of 'I alone am the honored one under heaven and on earth.'