We are ready to invade enemy territory.

We are conducting training to devise strategies against hypothetical enemies.

He lost his job, but he believes in the saying 'when one door shuts, another opens' and is looking for new opportunities.

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

I attended an awards ceremony yesterday.

It's difficult to solve this formula.

We attended his memorial service.

The calculation of determinants is an important part of mathematics.

I learned how to create formulas in math class.

He created a formula to solve the problem.