Answer:
A.The hole in the ozone layer
Explanation:
• Montreal protocol is an international treaty that was signed to control the use of substances that are resulting in the depletion of the ozone hole.
This treaty was signed in the year 1987 and became effective form 1989.
• Since the time that this treaty has come into force, there has been a significant improvement in the ozone hole that was observed over Antarctic as it's size has decreased.
• This improvement has been possible because the treaty helped to phase out chemicals such as chlorofluorocarbons, carbon tetrachloride, etc. that are responsible for ozone hole depletion.
I'm not entirely sure on this one... But I think it's 1. cell division helps animals repair old cells..
like please
Get to know your patient, learn more about it. that will show that you support his/her believes.
Theories cant become laws because they are just testable questions and opinions
The answer is d or c but I think it’s b. Hope this helps!