1.) C
2.) B
3.) I would assume A, as it goes with the answer to question 2.
Answer:
C. To find out if the call of an animal is missing
Explanation:
The more scientists listen to these kinds of recordings, the more they notice when an expected call is missing.
I hope this helps you in any shape or form.
The primary problem is the greenhouse effect. Greenhouse effect is when some gases (including CO2) absorbs some portion of sun's heat to make the atmosphere warm to support life. But when the amount of CO2 etc. increases in the atmosphere, it heats up more than it is required. So, by limiting CO2 emission, we can solve this problem.
<span>revise the structure of your topics by making the progression more logical</span>
