Question

fill in the blank question
when picking up an unknown object, it may be difficult at first since you dont know how heavy it is. eventually you can lift it up, due to a process called recruitment, during which more and more are activated resulting in stronger and stronger muscle contractions.

Explanation:

In muscle physiology, motor - unit recruitment is the process by which more motor units are activated to increase muscle contraction strength. Motor units consist of a motor neuron and the muscle fibers it innervates.

Answer:

motor units