维护的关键是认真的计划，完整的文档资料和优良的程序设计 。

The keys to maintenance are careful planning, good documentation, and good program design.

youdao

维护的关键是认真的计划，完整的文档资料和优良的程序设计 。

The keys to maintenance are careful planning, good documentation, and good program design.

youdao