Question

how did the three nawab of Bengal encourage the trade
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Answer 1

All three Nawabs of Bengal realised the importance of trade and thus, provided all the facilities to the local and foreign traders. They built roads, thanas, etc. They even forced the officials of East India Company to obey the laws of the land and pay the same custom duty as payed by the local merchants.
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Answer 2

Answer:

All three nawabs of Bengal realised the importance of trade and thus, provided all those facilities to the local and foreign traders.