He is my close friend.

I'm taking care of my health by having an extra meal every day.

He is good at adding numbers.

He is good at solving addition problems.

My grandfather used to raise domestic silkworms and make silk.

Peroxidation is one of the chemical reactions, especially involved in the oxidation of lipids.

This apple is a countable noun.

I go jogging every day.

We are going on a trip together.

That is my personal issue.