What is a macron, this is a legit question

What three colors are on the rwandan flag that was adopted in 2001

Humans have built artificial levees along the mississippi river to protect themselves and their property from floods. however, these structures also modify inland and coastal regions by disrupting the natural flow of sediment. artificial levees along the mississippi river a. reduce the amount of sediment deposited on floodplains and increase the amount of sediment deposited at the river's mouth. b. increase the amount of sediment deposited on floodplains and decrease the amount of sediment deposited at the river's mouth. c. increase the amount of sediment deposited on floodplains and at the river's mouth. d. decrease the amount of sediment deposited on floodplains and at the river's mouth.

What is the large wooded land in central south america is called?