A general knowledge of the topography is, then, the main guide, enabling one to determine where the trail ought to go- must go.

因此，对地形的一般了解是主要指南，使人能够确定小径应该去哪里 - 必须去哪里。

Your eyes and your mouth show me that feelings are important to you, but your forehead shows me that common sense is your main guide in life.

你的眼睛和嘴巴告诉我情感对你来说是重要的，但你的额头告诉我理智才是你生活的主要指南。