Ibeen having a problem with this question can you me? ?

When comparing the digestive and urinary system, we can conclude that they both

What is the main difference between trace elements and the main elements that make up the body? 1) main elements consist of heavier atoms. 2) trace elements are only needed in small amounts. 3) trace elements consist of heavier atoms. 4) main elements are only needed in small amounts.

What is the medical term for the middle ear not being able to conduct sound vibrations to the inner ear