Answer:
That is administered and controlled
Step-by-step explanation:
A variable is the condition or a product that may vary without the influence of any investigator. Such variables can be found abundantly in our daily lives, ranging from air to sunlight. Controlling such variables ensures the limitation of their influence on the outcome of an experiment. In connection to this experiment, the variables that are controlled are the mineral content in the water, the amount of bacteria food, the amount of light and the the constant temperature of 20 degrees C.
If not administered or these variables controlled, the experiment would not clearly explain the impact of caffeine on the heart beat of the water fleas as other variables may have influenced it. Thus variables are controlled to study the singular impact of any agent or effect.
Stephen Crane was both a novelist and a C. reporter, although he left that other job and became a full time writer.
The pH of stomach secretion is low. This means it is acidic. Too much production can corrode the stomach wall. Therefore in such a situation drinking a basic solution with a higher pH neutralizes some of the stomach acidic secretions hence relieving the effect;
Acid + Base - Salt + Water
The first reason was that his theory of continental drift was just too weak for most geologists to accept. Even though he believed the supercontinent that broke up into different continents moved, he did not have a clear explanation to how the continents moved. The other reason is that some of his explanation clashed with ideas that were widely accepted in the science communities. He used similar fossils from different continents to back up his theory of continental drift. However, at that time, many scientists that had observed similarities in fossils in places like South America and Africa believed there were similar fossils in different continents because of a land bridge that were formed by two continents.
Many science communities believe that land bridges allowed migration of many different species and even people to one place to another by large bodies of water frozen by low temperature known as ice age.
Answer: b. reaction 3
Explanation: When an enzyme is present in a reaction acts as a catalyst, increasing velocity of reaction and decreasing the activation energy, when not present an enzyme the reaction velocity is very low and implies high activation energy, being unfavorable to the system
