Explain how early indus river valley civilizations used brick channels.

these brick channels were used in the process of irrigation!

Bricks channels were used for several reasons mainly for the water system and drainage system, these bricks were baked, both these system were constructed in the underground separately to prevent from getting flooded. The water system was used for household uses, drinking and public baths, the drainage system was used for sewage to throw dirty used water. It was seen that sanitation was maintained in the Indus valley civilization.

trade

explanation:

the right answer is the third one: turnpikes went short distances to connect markets. turnpikes, also known as toll roads, were very important for trade and transportation (of people, goods and products) in the 19th century, coinciding with the expansion towards the west. they contributed significantly to the economic development of the united states.