URGENT HELP FOR CBSE CLASS 10 SCIENCE

i was going through a reference book (xam idea) for reproduction questions and stumbled upon a question from 2019 as follows:

in the experiment "to prepare a temporary mount of a leaf....to show stomata", glycerine and safranin are used. When and why are these two liquids used?

Bhai this was toh practical topic how tf did it come in 2019 boards, what is the probablity of practical questions coming?should i leave it or do it someone pls say fast