Answer : When a raw egg is placed in vinegar then it dissolves the shell of egg and makes it a naked egg.
Explanation : The shell of the egg is made up of calcium carbonate and when placed in vinegar which is mainly made up of acetic acid, dissolves the outer shell covering of calcium carbonate and makes the egg naked. This makes the raw egg bouncy in nature.
Definitely cell phone reception! However books could be argued for since they also are a good more than a necessity. However the last 2 i believe would be classified more as necessities than goods.
~Hope this helps!~
Answer:
security supervisor should keep an eye on the team's activities on the ground and ensure that they are appropriately trained to engage with visitors, vendors, and employees.