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下り坂, くだりざか
1. downhill, downward slope, descent
2. decline, waning, ebb, (going) downhill
下坡的;下降的;下降过程、(天气)转坏;衰退、减弱、消退、(走向)下坡路
は
1. indicates sentence topic
2. indicates contrast with another option (stated or unstated)
3. adds emphasis
指示句子的主题;表示与另一选项(无论是否明确提及)形成对比;表示强调