11.
A smog that occurs due to low temperature and has reducing environment is

12.
The earth's radiation is often referred to as ________radiation, while the sun's radiation is often referred to as _________radiation.

13.
Increased surface UV leads to increased __________ ozone

14.
Photochemical smog is called

15.
The albedo of the earth's surface is only about 4%, yet the combined albedo of the earth and the atmosphere is about 30%. Which set of conditions below best explains why this is so?

16.
The slow rate of decomposition of fallen logs in nature is due to their

17.
A high Biological Oxygen Demand (BOD) indicates that:

18.
Thorn-forests are found in the _______ regions.

19.
Green plants are absent in deep sea. Why?

20.
Euro II standard refers to _________