He went to Tokyo a few days ago.

Ah! I left something behind!

He went on with his work calmly.

Understanding numbers is important for solving math problems.

He was bedridden with illness for several days.

I can't solve this problem because there are too many numbers.

I am majoring in auditory phonetics at university.

Articulatory phonetics is a study about the production of speech sounds.

Acoustic phonetics is the study of the physical properties of speech.

I am majoring in microbiology at university.