Attempts were made to calculate Earth's age from the thickness of surviving sedimentary rock and from the currentlevel of the oceans' salinity.
人们曾试图根据现存沉积岩的厚度和目前海洋的盐度水平来计算地球的年龄。
2
Consequently, children of a particular age cannot be expected to master educational material without taking into account their currentlevel of cognitive development.
因此，如果不考虑特定年龄段的孩子们目前的认知发展水平，就不能期待他们能够掌握教材。
3
The factory cannot continue its currentlevel of production.