Teaching BPSC बिहार प्राथमिक (1 to 5) शिक्षक भर्ती 4.0 Mock Test Environmental Studies Environment Pollution
Smoke goes up because :
1
Warm air is denser than cold air
2
Warm air is lighter than cold air
3
Warm air has higher volume than cold air
4
More than one of the above
5
None of the above