Do bear in mind, though, that at this time of year the weather is very changeable and if the cloud suddenly descends, it's all too easy to wander off the track.
但是要记住，每年的这个时候天气变化无常，如果乌云突然降落，就很容易偏离轨道。
2
Unfortunately, cloud computing's track record to date has hardly been flawless.
不幸的是，云计算在跟踪记录的实时性方面总是存在问题。
3
And they are held back by difficulties in keeping track of data and getting reliable information about what's going on across a cloud.