应当制定设备的（）和（），设备的维护和维修应当有相应的记录。经改造或重大维修的设备应当（），符合要求后方可用于生产。主要生产和检验设备都应当有明确的操作规程。生产设备应当在确认的（）使用。

Multipurpose Internet Mail Extension (MIME) is a (46) document messaging standard in the Internet enviroment, with MIME, users can send (47) Email messages that include audio, video, graph-ices, and text to any other user of a TCP/IP network. Richtext information can also be (48) into messages. It defines the fonts, formats, and (49) features of a document so the document can be easily (50) on many different types of systems.

（47）是（）

A.analog

B.many

C.multmedia

D.digital