不一定

• Occupation is more formal and is used additionally of work , which may not provide a regular income
  Occupation较正式，还可指不一定有固定收入的工作。
• However skilled he may be , he is unable to do his work well without a sense of responsibility .
  技术熟练不一定能做好工作，还要有认真负责的工作态度。
• The time at which the two reductive divisions occur is not necessarily coincident to the time of ovulation .
  两次减数分裂的时间不一定与排卵时间相一致。
• Her finely touched spirit had still its fine issues, though they were not widely visible .
  她那高尚纯洁的精神不虞后继无人，只是不一定到处都能见到罢了。
• Although it is not requited to have "odd numbered" moving averages, it is advisable to do so .
  虽然不一定要求用“奇数”来进行移动平均，但这样做是可取的。
• These vertices, however, may not be distinct, as in the case where the endpoints may coincide .
  但这两个顶点不一定是不相同的，譬如在两个端点重合时的情况。
• We should note that the elements of a flexibility matrix are not necessarily dimensionally homogeneous .
  我们应该注意柔度矩阵中的诸元素不一定是量纲完全一样。
• The above analysis may readily be extended to general plane disturbances not necessarily harmonic .
  上面的分析可以很容易地引申到普遍的而不一定是简谐的平面扰动。
• The battle, sir, is not to the strong alone; it is to the vigilant, the active, the brave .
  先生，不一定强者才会得胜，高度警觉、生气勃勃、勇敢无畏的人也会得胜。