The observed frequency increases when the source and observer approach each other and decreases when they move apart. this is called the what?
1) emission spectrum
2) doppler effect
3) wavelength

List the body systems that were affected during mauro prosperi's journey across the desert. describe how you think he was able to last as long as he did. think about how his body would deal with his environment and how mauro could work to conserve his energy resources.