Question o DDT was a highly successful pesticide used in 1940's until its ban in 1972. While highly effective against insects, populations of birds began to decline because of thinning eggshells. On top of that there were concerns about human health. How does the story of DDT show the importance of continued monitoring of ecosystems? O Monitoring is not important as long as a product is thoroughly tested before being released O Monitoring is important to make sure a product is effective O Monitoring is important to ensure a product does not have unintended consequences on an ecosystem O Monitoring is not important because any unintended damage can be fixed when discovered​

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.