Which of the following is used as an ‘anti-knock’ in automobile engines? automobile engines?

Which of the following is used as an ‘anti-knock’ in automobile engines? automobile engines?

  1. Tetramethyl silane
  2. Lead tetra-ethyl ✓
  3. Glycerol
  4. n-heptane

Explanation

Nigeria had sophisticated political systems before colonialism. Centralized states: Benin Empire (Oba with divine authority), Hausa city-states/Sokoto Caliphate (emirate system), Oyo Empire (Alaafin with checks from Oyo Mesi).

Decentralized systems: Igbo village democracy (council of elders, age grades, titled men), Tiv (segmentary lineage system). No kings, but effective governance through consensus and tradition.

All systems had checks on power, dispute resolution mechanisms, and economic regulation. British often misunderstood decentralized systems as “primitive” and imposed “warrant chiefs” that disrupted social order.