For economic reasons , we did much of the heavy work ourselves - transporting cement , sand , lime , and bricks from the foothills , tearing down the hut , mixing cement , filtering sand , and carrying bucketfuls of building material 为了节省开支,许多粗重的工作例如下山运水泥沙白灰砖,拆棚子拌水泥筛沙提灰桶等工作,我们都亲自动手。