The shop glass content including ballast source selection principle and ballast means of transportation.

铺碴的内容包括道碴来源地的选取原则和道碴的运输方法.

互联网

The selection principle is selecting stand from fine seed source and from them selecting fine individuality.

论述了优树选择应遵循优良种源区选择优良林分,优良林分中选择优良单株的系统选择原则.

互联网