Bonjour. je ne sais vraiment pas alors aidez moi s'il vous plait  ​

A) It’s important to cut a very thin section because if it’s too big section we gonna see nothing throught the microscope (because we know it work with light )
B) we use a drop of water as a lens
C) to keep solid specimens pressed flat
And for the latest i think you gonna see this in class with your professor