rarely or never
Some users routinely retweet many messages, however, most followers are passive and rarely or never retweet.
有些用户习惯于转发很多消息，而大多数关注者往往很被动，他们很少或者从不转发。
Right. I have witnessed some applications that in fact rarely or never throw exceptions.
是的，我知道有些应用程序极少或从来不会抛出异常。
What isn't as obvious is that, of those 100 features, a total of 64 percent are rarely or never used by any customer.
不明显的是，那100个特性中，客户几乎或从不使用的特性总共64%。