混凝土由哪几种材料组成？

混凝土由哪几种材料组成？

["1\u6c34\u6ce5\uff0c2\u7802\u5b50\uff0c3\u77f3\u5b50\uff0c4\u6c34\uff0c5\u5916\u52a0\u5242"]