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ながら， 乍ら
1. while, during, as
2. while, although, though, despite, in spite of, notwithstanding
3. all, both
4. as (e.g. "as always", "as long ago"), in (e.g. "in tears")
5. while doing something else (at the same time)
同时，……期间，一边……一边
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
