VOA慢速英语:盲人有机会重见光明

switch - n. a small device that starts or stops the flow of electricity to something (such as a lamp or a machine) when it is pressed or moved up and down

pitch black – adj. completely dark

flickers – n. (plural) a quick and unsteady movement of light

sidewalk – n. a usually concrete path along the side of a street for people to walk on

crosswalk – n. a marked path where people can safely walk across a street or road

pattern – n. a repeated form or design especially that is used to decorate something