At the end of the exercise, which trait allowed you to more easily tell which birds belonged to the same species? (The species name is not a trait!)

Birds with the same shaped beaks

Explanation:

since I'm assuming you're referring to finches, the species of finch is determined by the type of beak that they have which is related to their diet.

Energy does not disappear, the energy is transformed from one form into another form. When a car stereo is turned on, the car radio converts radio waves to electrical energy, next the electrical energy in transformed in sound. It means when someone turn on a radio we have electrical energy, which is transformed into electrical energy and then into energy acoustic.

The complete sequence of energy is:

First transmission sound energy is converted into mechanical energy then electrical energy in the microphone, next into radio waves that is electromagnetic energy. The aerials convert electromagnetic energy in electrical energy and next in magnetic and mechanical energy and finally in sound energy.