front 1 Oasis | back 1 a fertile area that rises in a desert whenever water is regularly available |
front 2 Wadis | back 2 a dry riverbed that fills with water when rare rain fall in a desert |
front 3 Semiarid | back 3 having lower temperatures and cooler nights than hot, dry deserts |
front 4 Vary | back 4 to show difference between things |
front 5 Millenium | back 5 a period of a thousand years |
front 6 Polytheism | back 6 the belied in more than one god |
front 7 Monotheism | back 7 the belief in one god |
front 8 Expand | back 8 to spread out; to grow larger |
front 9 Collapse | back 9 a sudden failure, breakdown, or ruin |
front 10 Hydropolitics | back 10 the politics surrounding water access and usage rights |
front 11 Fossil water | back 11 water that fell as rain thousands of years ago and is now trapped deep below ground |
front 12 Delta | back 12 an area where sand, silt, clay, or gravel is dropped at the mouth of a river |
front 13 Silt | back 13 small particles of rich soil |
front 14 Ergs | back 14 a large area of sand |
front 15 Nomads | back 15 a person who lives by moving from place to place to follow and hunt herds of migration animals or lead herds of grazing animals to fresh pasture |
front 16 Aquifer | back 16 an underground layer of rock through which water flows |
front 17 Hieroglyphics | back 17 the system of writing that uses small pictures to represent sound or words |
front 18 Caliph | back 18 the successor to Muhammad |
front 19 Demonstrate | back 19 to show |
front 20 Regime | back 20 a government |