【单选题】36 / 278倒L形肋形梁按翼缘高度确定有效翼缘时,采用?Ab+12hf′b+12h'_fb+12hf′Bb+5hf′b+5h'_fb+5hf′正确Cl0/3l_0/3l0/3Db+snb+s_nb+sn参考答案B参考解析b+5hf′b+5h'_fb+5hf′,不是 b+12hf′b+12h'_fb+12hf′。