Hxen.com's tips：Every day persisted can learn English well!-->■Learn English Everyday■
drainage – n. process of removing water or liquid from a place
glacier – n. very large area of ice that moves slowly down a slope or valley or over a wide area of land
greenhouse gases – n. carbon dioxide and other gases that scientists have linked to rising global temperatures
metropolitan – adj. relating to a large city
levee – n. wall made of earth or other material built to keep water from flooding an area
elevate – v. lift up
pave – n. cover earth with a material to form a hard surface
impervious – adj. not allowing liquid to pass through
regulate – v. make rules or laws to control something
infrastructure – n. the basic equipment and structures (such as roads and bridges) needed for a country or organization to function properly
