Answer: 13-d :D
Explanation: A diaphragm allows different amounts of light to pass through the slide.
Can cause acid rain because the chemicals mix with the water vapor
He La cells have play important role in the study of cancer and even in cancer therapies. He La cells are also used to diagnose trisomic disorders such as Down's Syndrome with the help of chromosome banding. Some genes present in the He La cells are used as markers and compared with the other cell line in question. Presence of the marker for Down's syndrome in the cell in question shows that the person is suffering from the disease.
Answer: Smooth Muscle
Explanation: Smooth muscle cannot be controlled consciously and thus acts involuntarily.