单项选择题
A.0.5B.0.6C.0.7D.0.8
A.E/(1+μ)B.E/(1+2μ)C.E/(1-2μ)D.E/(1-μ)
A.Eμ/(1+μ)/(1-2μ)B.Eμ/(1+μ)C.Eμ/(1-2μ)D.Eμ/(1+μ)/(1+2μ)