C. highly professional

D. perfect and successful

27. The letter was written to _____.

A. ask for a pay rise

B. complain about working overtime

C. apply for buying office equipment

D. provide some suggestions about work

Thanks to services like Spotify, iTunes and Pandora, most people have given up discovering new music and instead chosen to depend on ready-made playlists or recommendations (推荐) made by others. Now thanks to the "Listening Tree", music lovers can re-discover the pleasure of discovering their own musical treasure.

Located in the courtyard of the Bunkhouse Saloon in downtown Las Vegas, the permanent installation (装置) is the invention of George Zisiadis. The San Francisco-based artist who specializes in unusual urban art projects wanted to provide listeners with a special experience that would allow them to escape from their busy lives and also find themselves through the songs they connect with.

The "Listening Tree" consists of 15 headphones. Passersby are encouraged to put a pair on and rock out to a random (随机的) song. Staying true to his purpose of creating musical spontaneity (自发性), Zisiadis makes sure that each set of headphones belts out a different tune. This encourages visitors to move around from