If a product contains bleach (peroxide), it will whiten your teeth. But not all treatments are created equal. It's the concentration or percent of hydrogen peroxide a teeth-whitening system contains and the amount of time it's in contact with your teeth that determines its effectiveness.
Definition of fecund - producing or capable of producing an abundance of offspring or new growth; highly fertile Definition of fecund - producing or capable of producing an abundance of offspring or new growth; highly fertile
The adjective fecund describes things that are highly fertile and that easily produce offspring or fruit. Rabbits are often considered to be fecund animals, and you may hear jokes in poor taste about people reproducing like rabbits if they have a lot of children.