16. Of the following atmospheric gases, there is one whose percentage volume is not
influenced by human activities. Identify it.
a) Ozone
b) Methane
c) Carbon dioxide
d) Oxygen
l7.A climax vegetation l which its characteristic reflect the influence of human
activities is considered as:
a)-C1imatio climax
b) Sub-climax
c) Plagio-climax
d) Mono-climax
18.Which ofthe following soil pH values is suitable for agriculture?
a) 1—4
b) 5—7
0) 6—8
d) 9 _ 11
19. A process by which sand and rocks particles are carried by wind in desert is lasted against rock outcrop resulting in catching and removal of particles is called:
a) Attrition
b) Abrasion
c) Corrosion
d) Deflation
20.Which of the following is the dominant texture of a soil in a region dominated by high-intensity physical weathering?
a) Clay
b) Sand
c) Silt