不一定

• A regimen that suits one person will not suit another .
  适合这个人的饮食制度不一定适合另外一个人。
• I do not think we will succeed but let us try anyway .
  我想我们不一定能成功，但是不管怎样还是试试吧。
• He does n't lend his book to anybody .
  （但anybody用降调读，则anybody便等于everybody）他的书不一定谁都借。
• Each of the following events is possible but unlikely .
  以下诸事件中，每一件都是可能发生，但又不一定发生的。
• Obviously these meridional planes need not be horizontal and vertical .
  显然，这些子午面不一定是水平的和垂直的。
• The problem may not arise , but there is no harm in keeping our powder dry .
  问题不一定会发生，但有备无患并无害处。
• The above views may or may not be correct , they are only for your reference .
  以上看法不一定符合实际，仅供你们参考。
• " race " suggests a need to run very fast , not always in competition .
  “赛跑”指有快速跑的必要，但不一定总是指比赛。
• Those commonly acclaimed as "great leaders" are not necessarily good men .
  那些平时被誉为“伟大领袖”的人，不一定是好人。