2, Tiantishan Airlines, interpreted as a metaphor for long-distance travel, experienced a long journey.
3, wading mountaineering, the interpretation is to describe the hardships of the journey, but also to describe the continuity of the journey.
4, good advice, interpretation means that it is as hard as climbing a mountain, and it is difficult to learn well.
5, over the mountains, the definition is to describe the hard work of field work or journey.
6. Stairs and ravines are defined as describing the hardships of mountaineering.