The sentences are invalid and unsound.
<h3><u>Explanation</u>:</h3>
The fire is defined as the vigorous oxidation of a substance. Now oxidation can occur in presence of any oxidising agent. Like magnesium in presence of nitrogen in high temperature with a dazzling brownish flame to produce magnesium nitride. So fire can be produced in absence of oxygen.
Oxygen is present everywhere in world. So production of a whole room without oxygen is very tough to produce and costly process. So its very unsound.
Answer:

Explanation:
The problem tell us that the temperature as function of time in downtown mathville is given by:

The average temperature over a given interval can be calculated as:

Where:

So, the initial temperature in this case, would be the temperature at noon, and the final temperature would be the temperature at midnight:
Therefore:


Hence, the average temperature between noon and midnight is:

Answer:
Explanation:
The coordinate sketch for the system is shown in the attached file below. Also, in the cartesian coordinate system, since the height is less than the length and width, we did neglect the height. Thus, we eliminate the height and converted it to a two-dimension.