料为A3的等截面直杆,若已知E=200GPa;σP=200MPa:,横截面面积为A;如果在轴向拉力F的作用下,其相对伸长为ε=0.009,各横截面上的正应力的大小可根据( )。
A campus emergency ______ occur at any time of the day or night, weekend, or holiday, with little or no warning.
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