
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

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system
A biology interest group conducted an exploratory experiment on the topic of "The Relationship between the Quantity of Yeast Population and Time in Culture Medium".
Experimental materials and tools: Yeast strains and sterile culture medium, test tubes, hemocytometer (the counting chamber is a 1mm×1mm square grid composed of 400 small squares), pipettes, sterile water, trypan blue dye (which does not stain living cells), microscope, etc.
Method of yeast microscopic counting:
1. Hemocytometer: A glass slide with tiny square scales for counting microorganisms under a microscope.
2. Drop the culture medium containing yeast on the counting board, count the number of yeast in one square, and then estimate the total number of yeast in the test tube. Observe continuously for 7 days and record the values daily.
Based on the above description, answer the following questions:
(1) This experiment did not set up a control experiment because . This experiment (fill in "needs" or "does not need") repeated experiments because .
(2) Before drawing the culture medium for counting, the test tube should be gently shaken several times because . If there are too many yeast cells in a small square to count clearly, the measure that should be taken is 
(3) On the 5th day, a student used the hemocytometer for counting as follows:
① Shake the test tube to mix, take 1mL of culture medium and dilute appropriately (a few drops of trypan blue dye were added to the sterile water of the diluted sample).
② First, place the cover slip on the counting chamber, use a pipette to drop the diluted culture medium at its edge, allowing the culture medium to seep in by itself. Excess culture medium is absorbed with filter paper (absorbent paper) to make a temporary slide.
③ Under the microscope, observe and count: only count the yeast that are (fill in "stained" or "not stained") blue. When counting a sample diluted 10 times on the hemocytometer, it was found that the average number of yeast in one small square (under the cover slip, the culture medium thickness is 0.1mm) is 5. Based on this, estimate the total number of yeast in 10mL of culture medium.

Present the answer in LaTex format: \boxed{Your answer}
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