I always keep a backup copy on disk.

【on】我总是给计算机磁盘留个备份。

Unfortunately, this means that if paternal copies of the genes don't get expressed, then there aren't any backup copies being expressed, and so no copies get expressed!

不幸的是，这就意味着在母源基因未表达的情况下，如果父源基因也没有表达的话，这些基因就无法表达了。

Technology writer Jack Schofield said that " data doesn't really exist unless you have at least two copies of it" , so it's important that we keep backup copies of what is important to us — probably more than one.

科技作家杰克·斯科菲尔德说过，“除非你有至少两份数据副本，否则数据并不真正存在”，因此，我们必须为对我们重要的东西保留备份副本——可能不止一份。