First bas指拉手，接吻，firstadj.第一的；最初的adv.首先；第一n.最初；(序数词)第一First degree burn of back背部一度烧伤first ionization constant一级电离常数first aid for the wounded战伤急救first category gassy mine一级瓦斯煤矿first-line form advance首行进页first-order modal logic[计] 一阶模态逻辑first wedding anniversary结婚一周年纪念日first restricted indorsee[法] 第一限制背书人First Battle of Lushunkou第一次旅顺口之战(1894)First trimester screening早孕期筛查

1. The blue first coat bled into the white.
   第一层蓝色渗入了白色涂层。
2. The first layer is to prepare the site for concrete placed under ground to secure the structure.
   第一层为现场混凝土置于地面保障体制。