Below is a list of materials and their indexes of refraction. The substance that is the most optically dense is
a) water, n = 1.33
b) glycerin, n = 1.47
c) glass, n = 1.65
d) sodium chloride, n = 1.53
e) zircon, n = 1.92

as a general rule, scissors have blades less than 6 in (15 cm) long and usually have handles with finger holes of the same size. shears have blades scissors used to cut hair or fabric must be much sharper.

the answer is f1 and d2 because if you put equal force on those two points the beam would balance trust me on this