Similarites
*Annual flooding left fertile soil
*Surplus of food allowed specialized jobs
*Used the rivers for trading
*ALL worshiped many gods
*Built large temples
*They had rulers
Differences
*All had used different rivers
*Indus Valley; Cities were planned in a grid
*Believed in afterlife
*3 or the 4 civilizations fell
this is just ideas of similarities and differences, sorry if this isn't all that you wanted or expected, i am still working on mine, but this can help you along the lines, i can try to write something if i finish mine early.
Hope this helps :)
"<span>b. The Germanics lacked loyalty to Rome and sometimes bought against the empire" is the best option from the list, since the Germanic tribes had very little connection to Rome or its empire and were just interest in getting paid.</span>
While competition may be hard for the individual, it is best for the race, because it insures survival of the fittest!