Strabo the geographer, writing in the first century, described the city walls high on the crest of a hill, as being steep to the very top and difficult to ascend.
斯特拉波，地理学家，在一世纪的时候写作形容山脊上的城市高墙陡峭至极，难于攀登。
2
As we rode, I used the zoom lens on my camera to scan the crest of a hill above us.
行进中，我通过相机上的变焦镜头扫视我们上方的山峰。
3
Just before you crest a hill or reach the end of a speed interval, your lungs go into overdrive.