Southwest asia and north africa often receive water from sources outside the region. which of the following statements is not true? a. the tigris-euphrates river system is fed by seasonal rainy area of the ethiopian highlands. b. the nile river is fed by lake victoria. c. the nile river is fed by seasonal rainy area of the ethiopian highlands. d. the tigris-euphrates river system is fed by snowmelt of the mountains in turkey and iran.