The most important severe hazard risk is the ground contact condition which arises in transmission poles, fence posts and railway sleepers.

 
  • 危害木材最严重的情况,是在木材与地基接触的条件下发生的,为通讯电杆,栅栏柱材和铁路枕木。
今日热词
目录 附录 查词历史