A.真實(shí)性 B.代表性 C.經(jīng)濟(jì)性 D.及時(shí)性
A.≥235MPa B.≥27J C.≥345MPa D.≥34J
A.10×10×55mm B.10×7.5×55mm C.7.5×7.5×55mm D.10×5×55mm