《规范》对砌体局部抗压强度提高系数______

A.f_tαb²h
B.f_tb²(3h-b))/6
C.0.7f_tb²(3h-6)/6
D.f_tb²(b₁-b)/2

A.f_yA_s≤α₁f_cb^"_fh^"_f
B.M≤α₁f_cb^"_fh^"_f(h₀-h^"_f/2)
C.f_yA_s＞α₁f_cb^"_fh^"_f
D.M＞α₁f_cb^"_fh^"_f(h₀-h^"_f/2)