Teaching BPSC बिहार माध्यमिक TGT (9 to 10) शिक्षक भर्ती 4.0 Mock Test General Knowledge Geography (World Geography) Biogeography
Which layer of the soil has maximum concentration of humus?
1
Weathered rock material
2
Top soil
3
Parent rock
4
More than one of the above
5
None of the above