Due to frequent changes in, or varying combinations of, some types of equipment such as avionics and instrumentation, ones or more separate documents for these products may be required.
由于某些类型的设备如航空电子设备和仪器仪表的频繁变化或不同的组合，这些产品可能需要一个或多个 单独的文档。
A.One or more separate documents for some types of equipment such as avionics and instrumentation may be required because they change frequently, or they have various combinations. B.Some types of equipment such as avionics and instrumentation are changed regularly or combined in different forms requiring to have one or more separate documents. C.Some types of equipment such as avionics and instrumentation are often revised or combined differently to require one or more separate documents.正确答案A
