Select ALL of the TRUE statements regarding microscopy (Mark all that apply) 

a When cleaning a microscope lens you should use only lens paper in order to avoid scratching the lens 

b A monocular microscope has a single ocular eyepiece 

c The objective lens is the lens at the top of the microscope that you view the specimen through 

d Because most cells and microorganisms are somewhat transparent, dyes and stains may be used to help visualize them or differentiate cellular features 

e When viewing a sample at a high power objective, you should only use the coarse adjustment knob to move the stage 

f An electron microscope visualizes a sample using a laser to excite fluorescent material within the sample