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動き出す， 動きだす， うごきだす
1. to start to move, to get going, to come alive
开始动，开始前进，开始活跃起来
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
