Respuesta :

Answer:Muscles relax and contract when one muscle pulls and moves your body part and if you want to do the opposite movement the opposite muscle contracts, allowing the first muscle to relax.

Explanation:

Answer: Skeletal muscles only pull in one direction.

Explanation: For this reason they always come in pairs. When one muscle in a pair contracts, to bend a joint for example, its counterpart then contracts and pulls in the opposite direction to straighten the joint out again. Hope this helps! :) If not, I am sorry :( If it does, Your Welcome!