業主在現場安裝工程開工前60天，支付我公司此部分合同總價（676臺SUPERSTRUCTURE現場安裝總造價）20％的工程預付款，我公司進場進行安裝準備。我的翻譯：The owner shall make the advance payment which is 20% of contract total price (the total cost of 676 superstructures installed on site)of this part 60 days before start installation on site, we approach the site and make the preparation for installation.