Another requirement needs to be satisfied to pick out the lowest cost one from all the providers with satisfied response time.
需要满足另一个要求，才能在满足响应时间的所有提供商中挑选最低成本的提供商。
2
This is two requirements; one is a functional requirement specifying what the system should do, and the other is a user interface requirement specifying the time format.
这是两条需求，一条是功能性需求，指定系统要做什么，另一条是用户界面需求，指定时间格式。
3
A requirement of a recovery log is that only one server has access to it (either for recovery processing or standard logging) at any time.