There is also a doubler feature at no additional cost.

还有一个额外的功能，在没有成本加倍。

Treat others sincerely you can get times doubler get one's own back!

真心对待别人你会得到双倍的回报！

A safe and feasible construction scheme is put forward for ship strengthened by doubler strake and its later repair.

对需要用复板条加强的船舶及其以后的修理工作提供了一个安全可行的施工方案。