basin: area of land drained by a given river and its branches;area of land surrounded by lands of higher elevation.（盆地）
bay: part of a large body of water that ectends into a shoreline,generally smller a gulf.（海湾）
canyou:deep and narrow valley with steep walls(峡谷)
cape:point of land that extends into a river ,lake,or ocean(海角, 岬)
channel: wide strait or waterway between two landmasses tha lie close to each other;deep part of a river or other waterway. (海峡)
cliff: steep ,high wall of rock ,earth, or ice.(悬崖)
continent : one of the seven large landmasses on the earth.(大陆)
delta: flat ,low-lying land built up from soil carried downstream by a river and deposited at its mouth.(三角洲)
divide : strech of high land that separates river system.(分水线)
downsteam:direction in which a river or stream flows from its source to its mouth(下游)
elevation: height of land above sea level(海拔)
Equator: imaginary line that runs around the earth halfway between the North and South Poles;used as the starting point to measure degrees of north and south latitude.(赤道)
glacier:large,thick body of slowly moving ice.(冰河)
gulf : part of a large body of water that extends into s shoreline, generally larger and more deeply than a bay(海湾)
harbor: a sheltered place along a shoreline where ships can anchor safely.(海港)
highland :elevated land area such as a hill, mountain ,or plateau
hill: elevated land with sloping sides and rounded summit: generally smaller than a mountain.(丘陵，小山)
island： land area ,smaller than a continent ,completely surrounded by water.(岛)
isthmus: narrow strech of land connecting two larger areas (地峡, 峡部)
lake: a sizable inland body of water..
latitude : distance north or south of the Equator,measured in degrees.(纬度)
longitude: distance east or west of the Prime Meridian measured in degrees.(经度)
