The belief that we can always start over – that things can always be made better – has been a defining characteristic of the United States and, at times, our greatest strength.
In most metals these rows can readily slip past one another, a characteristic that will lower the overall strength of the material.
在大部分金属中，行列可以很容易的相互滑动，这一特性会降低金属的总强度。
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In a previous study, Trinkaus found that shoe-wearing and barefoot human groups show characteristic differences in the size and strength of their middle toe bones.