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.

He is suffering from lung cancer.

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.