Is it true or false that the life of hawk bells can be lengthened by annealing them?

The assertion that the life of hawk bells can be lengthened by annealing them is true. Annealing is a process that involves heating a material and then cooling it slowly, which can relieve internal stresses and refine the structure of the material. For hawk bells, which are often made of metal, this process can improve durability and resistance to wear and tear. Consequently, by enhancing the physical properties of the metal, annealing can effectively extend the lifespan of the bells, making them more suitable for the rigors of falconry.

Regarding the other options, while they touch on specific conditions like the composition of the bells, the broad application of annealing to lengthen the life of metal bells stands as the most accurate and universally applicable statement.