was the first candidate to successfully use social media to mobilize voters and win the presidency. Social media also can help protest movements when videos and images go “ .”

In 2015, an online petition started by a New York City construction worker resulted in increased funding of .

✔ Barack Obama

✔ viral

✔ health benefits

Which one of the following was not a reason for the emergence of the single-family peasant farm as the basic unit of agricultural production in the early middle ages? select one: a. the mounted soldier made warfare expensive, so many warriors became full-time farmers. b. the declining birthrate made it necessary for entire families to work in agricultural production. c. horses made it easier, although more expensive, for farmers to support themselves. d. it was more economically feasible for landowners to rent their land to farmers. e. villa owners could no longer purchase slaves.