答案:B
解析:
Every cube has 6 identical square faces. Since the total surface area of this cube is 54 times (x^2), each face has area (54 times (x^2)) over 6 equals 9 times (x^2). Therefore, each edge has length square root (9 times (x ^2)), or 3 times x. The volume is (3 times x) ^ 3, or 27 times (x^3).