The chemical structures that form the units of DNA and RNA and that encode genetic information i.e. the bases that make up the base-pairs are A, G, T, C and U (see DNA).
形成DNA、RNA单体以及编码遗传信息的化学结构，也就是组成碱基对的碱基包括A、G、T、C、U。
2
S. G. iron mould platens and toggles after cutting by computer controlled machine, form precious clamping unit.
球墨铸铁模板及机铰经电脑机床加工，组成精密锁模系统；
3
For metal material, give the form of the material, e. g. steel coil, rod.