How did smallpox affect the people in the past?
Answers
Answer:
Smallpox is the only human disease that has been successfully eradicated. Smallpox, an infectious disease caused by the variola virus was a major cause of mortality in the past, with historic records of outbreaks across the world. Its historic death tolls were so large that it is often likened to the Black Plague.
Answer:
(i) Environmental aspects must be carefully looked into before building
huge dams.
(11) Most industries are concentrated around coal mines.
(1) Petroleum is referred to as “black gold”.
(iv) Quarrying can become a major environmental concern.
Distinguish between the followings.
(i) Conventional and non conventional sources of energy
(ii) Biogas and natural gas
(iii) Ferrous and nonferrous minerals
(iv) Metallic and nonmetallic minerals