Teaching BPSC बिहार माध्यमिक TGT (9 to 10) शिक्षक भर्ती 4.0 Mock Test General Knowledge Indian Geography Indian Economic and Human Geography
Which of the following type of coal is called a 'black diamond'?
1
Anthracite
2
Sub-bituminous
3
Bituminous
4
More than one of the above
5
None of the Above