(S (S (PP (PP (BASENP (NN ３) (NN 月) (NN 中)) (IN の)) (BASENP (DT ある) (NN とき))) (COMMA 、) (S (PP-SBJ (NP (PP (NP (S-REL-NSBJ (VP (VBV 離れ) (VP (MD た)))) (NN 村)) (IN の)) (NN 住民)) (IN が)) (VP (PP (NP (S-REL (PP-SBJ (BASENP (NN 鉛) (NN 濃度)) (IN の)) (ADJP (JJ 高い))) (NN 地域)) (IN で)) (VP (ADVP (NN 違法) (INRB に)) (VP (PP-OBJ (NP (PP (BASENP (NN 金)) (IN の)) (NN 採掘)) (IN を)) (VP (VBV 始め) (VP (MD た)))))))) (PERIOD 。))
3 月 中 の ある とき 、 離れ た 村 の 住民 が 鉛 濃度 の 高い 地域 で 違法 に 金 の 採掘 を 始め た 。
Sometime during March residents of remote villages began illegally mining gold in areas of high lead concentration .