Why can't a corona virus that infects a bird infect a human?

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

Frictional forces acting on an object are often converted into energy, which causes the temperature of the object to rise slightly.

How do you know when a chemical reaction has occurred