Ozone layer depletion was not noticed until 1979, while CFC’s have been around since 1920s because CFCs take time to enter the stratosphere and remain there for at least 60 years after their initial release.
Option: A
Explanation:
Ozone layer is found in stratosphere. Ozone plays a dual role in the environment. When it is in the ground surface zone it is a harmful gas but when its in the atmosphere it is a life saving layer which absorbs UV rays and protect human beings and animals from the harmful affect of poisonous gases.
Though ozone layer started depleting from 1920. But it came into notice from 1979 as CFCs take time to enter the stratosphere and remain there for at least 60 years after their initial release.
Answer:
Wastewater from fracking operations is injected into porous rock formations, which can induce seismic activity.
Explanation:
- The environmental concerns of the fracking can be linked to the increase of the potential for the oil spills that harm the coil and the surrounding vegetation and can cause the earthquakes due to the high pressure that is used to extract the oil and the gas from the rocks and storage of the excessive wastewater on site.
The Basin System of Irrigation was d<span>eveloped thousands of years ago.
It is now used only in parts of southern Egypt and northern Sudan. It only supports one main crop because it is dependent on the annual flooding of the Nile.
TRUE :)</span>
Answer:
A and D
Explanation:
because they prodouce what consumers demand and what they think is nessary.