2楼: Originally posted by befair at 2013-12-26 12:05:51
没有上下文，只能逐字分析：
concrete 做名词，是混凝土，作形容词是具体的（相对于抽象的）
sound 做名词是声音，作形容词是指坚实的、有基础的，比如说a sound design， 一个牢靠的设计
concrete sound 还请楼 ...

3楼: Originally posted by zxc0016610 at 2013-12-26 12:42:19
In general, concrete must be clean, dry and sound before a coating is applied to it. “Clean” means that there is no foreign matter, such as dust, dirt, grease, or oil, on the concrete. “Dry” mea ...