Graffiti （涂鸦）
Street art is a very popular form of art that is spreading quickly (quick) all over the world. You can find it on buildings, sidewalks, street signs and dustbins in many big _____1____(city) of the world. Street art has gained great ____2___ (popular). Even art museums and galleries are ____3____ (collect) the works of street artists. Street art started out very ____4____ (secret) because it is illegal to paint public and private property without permission. People often have different ___5____ (opinion) about street art. Some think it is a crime and others think it is a very ___6____ (beauty) new form of culture.
Art experts claim that the ____7___ (move) began in New York City in the 1960s. Young adults____8__ (spray) words and other images on walls and trains. This ____9____ (color), energetic style of writing became ____10____ (know) as graffiti.

2、____.