The skeletal, nervous, and muscular systems are represented as layers because . Thank you for anybody that helps

the answer is :

the alkaline earth metals (beryllium (be), magnesium (mg), calcium (ca), strontium (sr), barium (ba), and radium (ra)) are a group of chemical elements in the s-block of the periodic table with very similar properties: shiny. silvery-white. hopefully this ? i didn't fully understand the question

answerthe capacity to preform work;