Such estimates should be considered only as crude approximations.上述估算结果只能是粗略的近似值.There are two approaches generally used to arrive at these approximations.通常有两种方法用于获得近似解析式.They are not second - order approximations, but ...
They are not second - order approximations, but are exact for any amount of deformation.它们不是二次近似, 而是对任何变形量都成立的精确表达式.We do not have the true figures so we will have to make some approximations.我们没有真实的数字，因此只能作些粗略的估计。There ...