This unit group includes plumbing and other pipefitting trade contractors who own and operate their own businesses.

此单元组包括管道和其他管道安装行业承包商，其拥有并经营自己的企业。

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This unit group includes plumbing and other pipefitting trade contractors who own and operate their own businesses.

此单元组包括管道和其他管道安装行业承包商，其拥有并经营自己的企业。

youdao