Do you have a full detailed question? Or perhaps a photo of the question?
Answer: Positive
Explanation:Because of the gain in speed
A food web has many different links; It links off into different animals. Where as a food chains just a line of single animals that eat those animals for example: like hawks eat bunnies and bunnies eat grass and grass is the producer.
hope this helps u out...good luck
<span>Fireflies
use the bioluminescence to attract mates for mating hence key in reproduction.
Therefore, beetles from different species should have different lighting
patterns so that they can only attract mates of the same species. This would
avoid interspecies mating which would probably involved expending energy in
produce nonviable offspring which is inefficient (hence will be unfavoured
natural selection). </span>
The answer to your question is
x-rays