FIx my report ASAP ( 12 hours)

my professor did not give approval for my thesis because he need my to answer some questions and update my thesis 

1. Read the thesis paper very carefully.

2. answer the professor questions and find more research to support the answers.

QUESTIONS:

1. why did I choose 3-4 hours for food digestion, Is 3-4 enough to digest all the food in zebrafish?

2. Why did I choose 2 Zebrafish in each tank? 

I belive 2 fish will make the change in Oxygen measurements more, and make the observation more accurate. Because One fish in a big tank can will make the measurement less accurate( support with evidences) 

3. Is the measurement of 2 zebrafish is a good idea?why not 3 or 4 zebrafish?

I believe it will have the same effect, but to save the environment I will just use 2 zebrafish.( but find the evidence that 2 zebrafish is enough)

4. Does the size of the tank will affect the measurement of zebrafish?