25 Points Please Help ASAP! Will Mark Brainliest If All Are Answered!!

Two friends at different locations want to communicate with each other by sending low energy signals. which of the following methods can they use to communicate? a) produce x-rays using colliding electrons and send them to radios, which capture sound b) send messages using infrared radiation, which travel in the form of waves c) send radio waves through intervening media like radio and television d) produce sound waves using microwaves from heated objects

What provides structure to the human body?

Write the symbol for every chemical element that has atomic number greater than 3 and atomic mass less than 12.0 u.