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.
Answer:
d. this is one part of the cell cycle.
Explanation:
THE ACTIN has the active site to which the heads of the thick filament will bind.
The muscle is made up of two major protein fibers, which are the actin and the myosin. Muscle contractions occur when myosin and actin slide over each other in a series of repetitive events. The protein actin has a thin structure and is abundant in eukaryotic cells while myosin is a thick filament.
They do, but very slowly. Mostly when growing or wind is hitting it.
