But there can be no general rules, nor standard time-scale.
但是不可能存在普适的规则，也不存在标准的时间表。
2
Many scientists provided valuable research and input into the creation of the geologic timescale.
许多科学家为地质时间尺度的建立提供了有价值的研究和投入。
3
Such changes are all but invisible over the short timescale of modern observations, and, it is argued, they are usually obscured by innumerable gaps in the imperfect fossil record.