He had a dagger in his hand.

This problem requires solving a nonlinear equation.

This equation has nonlinear characteristics.

It is difficult to solve this nonlinear equation.

He drew a rhombus on the blackboard.

He likes to take a walk in the park at dusk.

He is receiving a basic living stipend.

Understanding geometric sequences is important for understanding mathematics.

He suffers from adrenal cortex insufficiency.

I lost my precious belongings.