It is also useful because the mold can be used over and over again to make exact copies of the ceramic form.

VOA: special.2009.09.09

That only strands that have this exact complement can form double stranded DNA.

这表示只有两条链的碱基对,完全互补才能形成DNA双链

耶鲁公开课 - 生物医学工程探索课程节选

If I'm talking about two DNA strands and they differ only in one or two base pairs they won't be exact complements and they won't form this double helix.

假设有两条DNA单链,有一两个碱基不能配对,它们就不能完全互补,也无法形成双螺旋形结构

耶鲁公开课 - 生物医学工程探索课程节选