She may even cross a valley to see how trees will look in a given density.
她甚至可以跨一个山谷，看看树，看看在给定的密度。
2
A new dispersion model is developed by adoption of assumption for cross-wind dispersion in VALLEY model, but the treatment of terrain influence is changed.
Mobile pipelines are equipped with suspending devices, and they are the most important part of the mobile pipeline, which are used to cross the valley.