[问答题] What’s the difference between casual listening and focused listening?

社会生产力，特别是（）的发展，是国际分工形成和发展的决定性因素。 什么是黑体？ What are some of the advantages of using a cassette recorder? （）是国际贸易和世界市场的基础。 What’s the difference between casual listening and focused listening?