Stream channels have three major zones, from their headwaters to the mouth, and each zone exhibits unique characteristics. a. True
b. False

These factors threaten north americas ecosystems

Which of the following types of nonrenewable fuel sources requires the storage of radioactive waste? a. coal b. nuclear c. solar d. oil

Which of the following statements best describes what is occurring in the land surrounding the sahara desert? a desertification is increasing, and the desert is expanding. b. fewer people are trying to farm in this semiarid region. c. the desert is shrinking with the increased use of irrigation. d. increased urbanization has resulted in decreased deforestation. select the best answer from the choices provided mark this and return save and exit next submit