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Annie is making a microscope slide. She puts a piece of sponge of the slide. Under the microscope, it looks like a black blob. She can't see any of the parts of the sponge. What is the best way to make the slide better?
a. use a well slide
b. turn the slide over
c. use a cover slip
d. use a smaller piece of sponge
d. use a smaller piece of sponge.