r

• let us suppose that with n objects and only wish to arrange a row of r of them. (r≤n).
  我们考虑从几个元素中只取r个（rn）排列一行的情形。
• He had been so obsessed with the mystery of the r document that love was the last thing on his mind .
  可是他的思绪被神秘的代号R密件缠住了，根本不想与妻子温存。
• At sufficiently high temperature and low pressure this ratio approaches the value r for an ideal gas .
  在足够高的温度和足够低的压力下，这个比值趋于理想气体的R值。
• The torque i acting on a particle is defined as the cross product of r and the force acting on the particle .
  作用于粒子上的力矩I定义为r与作用在粒子上的力的叉积。
• The integration corresponds to adding successive shells to the core until the core has radius r .
  这个积分相当于把一系列球壳加到球核上，直到球核的半径等于R时为止。
• The films are developed and the degree of fogging observed is a measure of the gamma-ray exposure .
  经显影之后，可以根据观察到的模糊发黑程度来确定r射线的照射程度。
• This snapshot function is usually represented by the pair-distribution function g(r)when suitably normalized .
  这个瞬时函数经过适当的归一通常可以表示为偶分布函数g（r）。
• The parity of the eigenfunction is found by determining what happens to the wave function when r is replaced by －r .
  本征函数的宇称可以这样确定：当r用r代替时看波函数的变化。