Questions

Yes, the given statement that water is more dense than cooking oil is TRUE as water more denser than oil it is sinked when it is poured in oil.

DPT refers to a class of combination vaccines against three infectious diseases in humans: diphtheria, pertussis, and tetanus.

Pertussis refers to whooping cough.

Free memory is maintained in linked lists, each of equal sized blocks. Any such block is of size 2^k. When some memory is required by a process, the block size of next higher order is chosen, and broken into two. Note that the two such pieces differ in address only in their kth bit. Such pieces are called buddies. When any used block is freed, the OS checks to see if its buddy is also free. If so, it is rejoined, and put into the original free-block linked-list.

India was one of the main centres of world trade and industry. Peter the Great of Russia was led to exclaim: “Bear in mind that the commerce of India is the commerce of the world and ... he who can exclusively command it is the dictator of Europe.”

An invention that improved safety for railway passengers is Air brakes. With the use of air brakes using compressed air, become more effective by preventing many train accidents.