2. "Crossing the Yellow River" and "Climbing Taihang Mountain" symbolize the poet's pursuit of ideals, while "blocking the river with ice" and "covering the mountain with snow" symbolize the poet's repeated setbacks in his pursuit.
The author takes this opportunity to express his hero's grief and indignation at losing his way, and because there is a famous saying "It's hard to walk" below, this sentence can be regarded as an inspiration. So this sentence actually uses metaphor and symbol.