Dad, what are you going to make today?

My sick father is seen by a doctor every day.

This ancient document contains the word 'father sound', which is no longer used in modern Japanese.

He understands the importance of learning.

He is majoring in psychology.

Gaku is my best friend.

He has a deep interest in archaeology.

He is good at geometry.

Differential geometry is a field of mathematics that studies geometric objects such as curves and surfaces using differential and integral calculus.

Understanding geometric series is important in learning the basics of advanced mathematics.