Only two markers of human activity are evident in the stratosphere.

They are indicated by .

Select one:
a. the condition of the ozone layer and the presence of spy planes
b. the flight of rockets and transmission of radio signals
c. the weather that we experience and commercial airplane flight

d. the presence of satellites and the International Space Station

Option A. the condition of the ozone layer and the presence of spy planes.

Explanation:

Stratosphere is very important layer because a very important gas i. e. Ozone is present. Ozone gas makes a layer around the earth which prevents the earth from harmful ultraviolet radiation of the sun. This radiation causes skin disease such as skin cancer. Aeroplane and jets also fly in this region.

the correct answer is b. possesses the characteristic of compartmentalization of organelles, wherein the organelles are bound by membranes.

explanation:

answer: 20 percent

the fish culture has become a developing commercial practice in developing countries which is already prominent in developed countries of the world. the major fish protein demand is being supplemented in developing countries is   fishing to meet the needs of the growing population. therefore, in some developing nations, the percentage of animal protein from fish in the diet can be as high as 20 percent.