He activates his brain cells by solving crossword puzzles every day.

I bought a new swim cap to swim in the pool.

The cell membrane protects the cell and controls the entry and exit of substances.

In English, adding 's' after a noun makes it a plural form.

This problem has multiple answers.

How is an adverb used in a sentence?

I learned double-entry bookkeeping at university.

A complex number is a combination of a real number and an imaginary number.

We are aiming for a society where all people can enjoy welfare.

He is suffering from lung cancer.