【单选题】5 / 7若dw−d0=0.2 md_w-d_0=0.2\,\mathrm{m}dw−d0=0.2m,按三心圆平拱式m=1.707(dw−d0)m=1.707(d_w-d_0)m=1.707(dw−d0),则mmm约为?A0.034 m0.034\,\mathrm{m}0.034mB0.341 m0.341\,\mathrm{m}0.341m正确C1.707 m1.707\,\mathrm{m}1.707mD3.41 m3.41\,\mathrm{m}3.41m参考答案B参考解析1.707×0.2≈0.341 m1.707\times 0.2\approx 0.341\,\mathrm{m}1.707×0.2≈0.341m。