Q.no. 24 ,26 please answer fast

​Q24. In the experiment to show CO₂ is released during respiration, the partial vacuum is created. Explain why.

Q26. A student has to perform an experiment on tracing the path of a ray of light passing through a rectangular glass slab for three different angle of incidence. Two of his friends suggest the following options to him:

      (A) Draw the incident rays corresponding to 20°, 50° and 70° as angles of incidence and fix the two pins on the incident ray just 2 cm apart.

      (B) Draw the incident rays corresponding to 30°, 45° and 60° as the angles of incidence and fix two pins on the incident rays nearly 8 cm apart. Which is the better option he should follow?

         Give reason in support of your answer.