1.   The propellant is needed to counteract these forces.

2.   Proposed a century ago by Einstein, dark energy may counteract forces such as gravity.

3.   Steel cables will be attached along one side of the beams and pulled taut with hundreds of tons of pressure to counteract the forces trying to make them bend.

4.   To better counteract these forces, Zarebski Zbigniew, general director of the mine, is overseeing a program designed to buttress chambers and reinforce the surrounding rock.