Sand Bags (IMAGE) Proceedings of the National Academy of Sciences Caption (A) Well-preserved 'sand bags', with the knots still clearly visible, the grass plants used are Triarrhena lutarioriparia. (B) A small proportion of rice remains discovered from the storage pit excavated at eastern Mojiaoshan, depth of the boxes around 10 cm. Credit PNAS Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.