You can solve the problem by using this method.

This company strictly adheres to the principle of fair trade.

He saved money using the 'hou' (alternative spelling of 'fran') to go to France.

He likes to learn new words.

He is good at speaking Spanish.

He can speak Japanese fluently.

He is good at solving trigonometry problems.

This library adopts its own classification method.

He surprised people by using magic.

Understanding patent law is important for protecting new inventions.