10. how did social studies cross over into science? hint what
was invented over 3000 years ago that societies needed for
their daily trading of goods? ( explain)

Barter system was invented over 3000 years ago which society needed for their goods trading through which social studies crossed the science.

Barter system existed centuries ago when coins were yet to be invented.  People did not have any currency back then. To make trading a successful practice, goods were exchanged for goods. That is, a person exchanging earthen pots for rice or wheat. The system worked for several centuries and had flaws of its own.

For instance, the trade itself wasn't always fair. The guarantee of the goods was not ensured. Nor was the reliability of the seller. Other than that, people had to find the sellers who would want to exchange with their goods. Despite everything, the barter system continued until coins were invented.

dear friend:

  i hope this letter finds you in soaring spirits and vibrant health. as you had expressed the wish to know about culture, traditions, and unity of india in your previous letter, in the following lines i have tried my best to give you glimpses of our culture, traditions, and unity. you will be amazed to know that our culture is the oldest culture in the world and the birth place of hinduism, buddhism, jainism, and sikhism. you won’t find any other culture as varied and multi-colored, multi-lingual as ours. each region has its own unique culture, traditions, language. there are 22 official languages in india.

  basically, india is a spiritual country with orthodox traditions. for example the people of india believe in traditions set by their wise forefathers. arranged marriages, joint-family system, universal brotherhood, vegetarianism, celebrating festivals such as diwali, holi, eid, etc., are the salient features of our culture and traditions.

  another unique aspect about our country is ‘unity in diversity’. in spite of the multi-lingual, multi-religious, multi-traditional, multi-cultural society, people live peacefully together, respecting one another’s views, cultures, traditions, and differences. i am sure you would love to visit india soon, and have a first-hand experience of the multi-colored culture. give regards to uncle and aunt. do visit india with your family and experience our hospitality.

your friend,

no the answer is c only objects touching the earth's surface can be acted upon by an outside force