That is a HYPOTHESES because it says "May Cause"
Your question should have a picture in other to answer the question:)
If the machine is working properly then that rules out 2, 3 and 4 as they are all technical problems and therefore it must be A there waves don't reflect of the stone properly and therefore no image is formed
Hope that helps
Answer:
1. They make up part of a negative feedback system that promotes insect population growth.
Explanation:
If the Martin becomes extinct, it will cause an increase in insect population, as there is no predator to maintain the population. A population growth of insects would be a problem as it will destroy crops and agriculture.
Answer
Volume. Just think about it, do any of the others make any sense?