UPSC Prelims Medieval History – 2023
1) Consider the following: 1. Aerosols 2. Foam agents 3. Fire retardants 4. Lubricants In the making of how many of the above are hydrofluorocarbons used? (a) Only one (b) Only two (c) Only three (d) All four Correct Answer: (c) Only three 2) ‘Wolbachia method’ is sometimes talked about