Answer:
2, that’s what the 2 means.
Explanation:
Essentially, a control variable is what is kept the same throughout the experiment, and it is not of primary concern in the experimental outcome. Any change in a control variable in an experiment would invalidate the correlation of dependent variables (DV) to the independent variable (IV), thus skewing the results.
Chemical digestion involves breaking down the nutrients into smaller cells
Physical digestion is using physical movements such as chewing and swallowing
Sterilization controls the microbial in this world
