How does phase contrast microscopy scientists to visualize difficult specimens?

The asnwer is Allows observation and study of living cells.

Explanation:

The phase contrast microscope allows observation of uncolored cells, which is very useful for the study of living cells. This type of procedure helps scientists study difficult samples, because most living organisms cannot be dyed or colored, since the dyes used could damage their cell structure and even cause them to die.

the actual answer was 160934