Question

how can you say that Harappan people had knowledge of trade? (2 points)

Answer 1

Typically because we read the reports of archaeological digs, wherein are reports of things being found that are derived from other places. If you find “foreign” stuff, then you assume foreign trade. It might, of course, be a result of foreign conquest, but that tends to be a sudden influx of loot at just one time: where the stuff is coming in over long periods of time we assume “trade.”

Also, we have other “digs” in other places, and if we see a balancing import of Harrapan trade goods, then you have a little confirmation: especially if you can see the trade as being in each case from the place where the stuff is common and cheap, and to the place where it is rare and probably has scarcity value.

It is a form of international trade statistix, built up one shard of pottery at a time. Archaeology used to be treasure seeking - but for the last century or so the diggers are after INFORMATION - not golden bangles - though they are very welcome finds, indicative of high status lives back then, there.

Answer 2

1) Because the seals and coins of harappan civilization is found on other palaces like Mesopotamia etc
2)archlogist find that harappan people trade with foreign people to buy goods like weapons etc