The correct answer would be the second option. The correct plan for his experiment would be that the temperature, the type of limestone, and the type of acid are controls. The amount of acid and the amount of damage to the limestone are variables. To determine the degree of damage of the acid it would be best that the amount of acid is the manipulated variable while everything else are assumed constant.
Answer:
I feel proud of Mt. Everest because it is the tallest mountain in the world and it is situates in Nepal. I am also feel proud of Gautam Buddha because Siddhartha Gautam born in Brahman family in Hindu religion but has sacrificed this luxurious life for the sake of humanity and noble cause.
