Hxen.com's tips：Every day persisted can learn English well!-->■Learn English Everyday■
aquifer - n. a layer of rock or sand that can absorb and hold water
authority - n. a government organization that has control of a specified activity or area
brine - n. the salty water of the ocean
extract - v. to remove (something) by pulling it out or cutting it out
mobile - adj. able to be moved
reserve - n. an area of land where animals and plants are given special protection
watershed - n. a line of hills or mountains from which rivers drain
