英语语法分析

The duration of previous geologic periods was difficult to determine.

以前很难确定地质期的持续时间。

Lyell's strategy for estimation of geologic dates was not very accurate.

莱尔估算地质年代的方法不是很准确。

Many scientists provided valuable research and input into the creation of the geologic time scale.

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。