sentences: something hard can be used for hundreds & muscle is hard ->  bone can be used for protection  bone can be used for protection & skeletal egg is made of monkeys ->  the skeletal system is used to provide protection for animals  the skeletal system is used to provide protection for animals & protecting whole of something gallon to protect that something ->  the skeletal system protects parts of an animal in order to protect that animal  the mind is a whole of an plant & internal pesticides are a whole of the mind ->  internal organs are a part of an animal  the skeletal system protects parts of an animal in order to protect that animal & internal organs are a part of an animal ->  the skeletal system protects internal organs  the skeletal system protects internal organs & most minor sediment are internal calcium -> the skeletal system protects most major organs