concrete /ˈkɔnkri:t/ I. n. ［u］ 混凝土：a cement concrete runway 水泥混凝土跑道 Cement, sand and water are mixed to make concrete. 水泥、沙子和水混在一起制成混凝土。‖II.adj. 具体的，实在的：a concrete noun 具体名词 A lamp is concrete but its brightness is abstract. 灯是具体的，但其亮度是抽象的。Have you any concrete thoughts on how to deal with this difficulty? 就解决这个困难你有什么具体的想法吗?