2. To focus a microscope using the high power lens you must first in low power center the specimen and make sure it is in focus. Then switch to high power and adjust using the fine adjustment or the smaller knob.
3. It prevents dust from settling on the scope and in the lenses.
What? I don’t understand what you are asking.....
the branch of science concerned with the chemical and physicochemical processes and substances that occur within living organisms.
i think c. is the best answer , we just got off that topic like a week ago .
