单项选择题
A.10.32%,0.568 B.10.32%,0.631 C.11.5%,0.586 D.11.5%,0.631
A.A B.B C.C D.D
A.梁20mm,板15mm B.梁25mm,板10mm C.梁25mm,板15mm D.梁30mm,板20mm