一心に (translations)→ absorbed busily eagerly fervently hard intently relentlessly so tensely
仔細に (translations)→ carefully circumspectly closely
耳を傾ける (translations)→ consult focus hearken listen react take
丹念に (translations)→ assiduously careful clever dutifully examination faithfully industriously methodically meticulously neatly patiently sedulously thoroughly
注意深く (translations)→ anxiously cautiously heedfully mindfully
熱心に (translations)→ actively alertly busy earnest lively seriously steadfast vigorously