Your best bet will be one of three materials, redwood, pressuretreated fir, and used rail ties.
你最好的选择将是三种材料，红木，杉木对待压力，并利用铁路关系之一。
2
When pressuretreated boards are sawn, entry points are created for rot and insects to take hold.
当压力处理的板锯，切入点是腐病和昆虫创建的把握。
3
The EPA says there is no need to worry about existing retaining walls, because there is no evidence that pressuretreated lumber poses any significant risk.