The correct answer is Metal.
Sound waves are vibrations which need medium to propagate. Higher the density of medium, the sound travels fastest. Sound travels fastest in solid than liquid and gas. Therefore, in this question sound will travel faster in metal because metal has higher density than air and water and it will not travel in vacuum as sound needs medium to travel.
the importance of this procedure is to get a set of data to compare your other test results to, like when they are active
Answer:
D) competition
Explanation:
They are going to be competing for their survival.
Hope this helps! :)
