She'd seen their kind used to concentrate the sun's energy to start a fire.

Concentrate your energy on things you can influence and change.

She had to concentrate all her energy on saving herself.

The position we had taken concentrated all our energies and heat.

A spell makes you concentrate your energy on a goal.

It seemed he was now concentrating all his energy on building more hotels in Europe.

"It makes sense for the city to concentrate its energies here."

"He has to concentrate his time and energy on the battleground states."

"I think we'd be better off concentrating our energy in other areas," she replied.

I concentrate my energy on those willing to change their life.