A constituent of the exhaust gases of motor vehicles which causes serious air pollution is

A constituent of the exhaust gases of motor vehicles which causes serious air pollution is

  1. water vapour
  2. oxygen
  3. carbon dioxide
  4. carbon monoxide ✓

Explanation

Before colonization, Nigeria had diverse political systems. Kingdoms: Benin Empire (sophisticated bronze art, divine king), Oyo Empire (checks on oba through Oyo Mesi and Ogboni).

Emirates: Hausa states became Islamic caliphates after Usman dan Fodios jihad (1804). Emirate system with religious and political authority combined.

Decentralized societies: Igbo had no central authority – village assemblies, age grades, and titled societies governed. This made colonial administration difficult.