Why had farming become unprofitable during this period?

Which of the following inventions most directly allowed ancient farmers to produce a surplus ?

The chinese exclusion act was the first significant law restricting immigration into the united states. why do you think the us government singled out chinese immigrants in particular for exclusion?

The oldest known mesopotamian civilization settled in areas along river banks or sea sides surrounded by mountains and deserts which two statements explain why three geographical features led to the rise of mesopotamian civilizations