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疲れる， つかれる
1. to get tired, to tire, to get fatigued, to become exhausted, to grow weary
2. to become worn out (of a well-used object)
3. to starve
感到疲倦、变得疲惫、感到疲惫不堪、变得精疲力竭、变得厌倦；变得破旧不堪(对于经常使用的东西而言)
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引き返す， 引返す， 引きかえす， ひきかえす
1. to turn back, to go back, to come back, to return, to retrace one's steps
折返，返回，归来，重返，原路返回
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
