Market regulation system was introduced by Ala-ud-Din Khilji. He was the second and the most powerful ruler of the Khalji dynasty that ruled the Delhi Sultanate in the Indian subcontinent.
Salivary glands of man are 3 pairs = 6. They are one pair of parotid glands, one pair of sub-maxillary or sub-mandibular glands and one pair of sub-lingual glands.