Obtain the value of the elongation of bars BC and AD , δBC and δAD , in mm:δBC=______ mmδAD=______ mm

Mars will not be visible（）. A: at elongation angles near 180° B: from quadrature to opposition C: at conjunction D: at oppositio

拉伸强度的英文是 A: tensile strength B: tensile yield C: elongation at break D: tensile fracture stress

Which part of translation involves the addition of amino acids to an existing polypeptide chain? A: initiation B: elongation C: termination D: transcription

常用的塑性判断依据是( )。 A: Elongation after fracture and section shrinkage B: Plastic and toughness C: Section shrinkage and plasticity D: Thermal expansion

Suppose that both the cross-sectional area A and the length L of two straight rods are the same, and the axial tension forces P at both ends of the two are also the same. Only the materials of the two rods are different. Which statement about the stress σ and the elongation ΔL of the two rods is right?__________