What are some sources of possible error in the replicated study when making comparisons to the original study?

The 2nd largest river in europe (that runs through 12 countries) is the river. question 13 options: rhine danube seine thames

Answer quickly! correct answers only! how did an agricultural surplus relate to expanded trade during the high middle ages? a)trade increased because surplus crops could be traded. b)trade decreased because surplus crops were needed to feed local populations. c)trade decreased because surplus crops led to an oversupply of grains that could not be sold. d)trade increased regionally but decreased globally because trade networks had shrunk.

Are people more motivated to change from positive or negative experiences, like slavery, womens rights, and any other historical movements/moments? i need more factual information than opinions.