Have you tried on the oviaducts im not sure but try it
Answer:
Diaphragm
Explanation:
This is also referred to as the iris.it is located under the stage of the microscope. It's main role is to control the quantity of light that gets to the specimen. The diaphragm is adjustable. Each if the 5 holes in the disc have varying diameter. And it is helpful for adjusting contrast and resolution as regarding the specimen
The main difference is that quotas restrict quantity while tariff works through prices