By using (26) , a 600M -byte music CD can be compressed to 50M bytes or less. It can be streamed (downloaded in chunks) so that you can begin listening to the opening bars while the (27) of the file arrives in the background. And, most important, the music files of this kind retain good listening (28) that earlier (29) schemes lacked. That (30) of features makes accessing and distributing music on the web practical for the first time.

A．difference

B．combination

C．addition

D．condition

在竣工验收前，对已完工程及设备进行保护所需的费用属于（）。

A．建筑安装工程措施费

B．建筑安装工程直接工程费

C．建筑安装工程现场经费

D．建设单位管理费