Answer:
1981
Explanation:
<em>"A new era in space flight began on April 12, 1981, when Space Shuttle Columbia, or STS-1, soared into orbit from NASA's Kennedy Space Center in Florida."</em>
D - Allow pH to change drastically.
The reason that we have buffer in our system is to protect AGAINST sudden change of pH
The Answer Is On This Link https://technet.microsoft.com/en-us/library/cc961723.aspx
The three types of point mutations that can occur during replication/protein synthesis such as Insertion, Deletion, and Frameshift.