单项选择题
A.205N/mm2,46.8N/mm2 B.212.6N/mm2,46.8N/mm2 C.205N/mm2,40.8N/mm2 D.215N/mm2,40.8N/mm2
A.3 B.6 C.9 D.12
A.内力改变,位移改变 B.内力改变,位移不变 C.内力不变,位移改变 D.内力不变,位移不变