可以有偿也可以无偿的合同是（）。

［A］ record player

［B］ radio

［C］ musical technique

［D］ music culture

A．生产关系一定要适合生产力性质的规律

B．价值规律

C．按比例分配社会劳动的规律

D．货币流通规律

［A］ the importance of cultural tools and technology

［B］ the cultural influence of the development of civilization

［C］ the focus of the study of the material culture of music

［D］ the significance of the research into the musical instruments

［A］ Reading of music notation has a great impact on musicians.

［B］ People may draw imspiration from it.

［C］ The music culture will be influenced by it in the end.

［D］ Songs tend to be standardized by it.

［A］ Sony’s Shopping Expedition ［B］ Sony: the Private Life

［C］ Who Drove Sony to Ground ［D］ Sony: Management by Impulse