工人们正在用钢筋加固这座老房子的地基。

The workers are adding steel ___reinforcement to strengthen the foundation of this old house.

给狗狗零食作为奖励是一种常见的正强化方法，会让它更愿意遵守指令。

Giving the dog treats as a reward is a common form of positive ___reinforcement that makes it more likely to follow commands.

前线需要更多的增援部队来抵御敌人的进攻。

The front line urgently needs more ___reinforcements to hold off the enemy's attack.