Which are human systems?
a the amazon rain forest
i the appalachian trail
the george washington bridge
the himalayas
the hoover dam
the north american free trade agreement
the san andreas fault
the suez canal

The cause of the intolerable acts was king george was furious about the boston tea party and closed the harbor and took away their self government until all the tea was paid for. the effect was these acts just stirred up more british hating feelings. now people in all 13 colonies were angry. b.