果树树种辨识
identification of species of fruit trees
林种树种
forest categories and tree species
引种树种
Introduced tree species
introducing afforestation tree species
主要桉树树种及其无性系
Major eucalyptus species and its clone
主要树种种群
major tree species population
NASA先锋太空计划
NASA Pioneer sapce missions
二叉树先序遍历
binary tree’s preorder traversal
科技先锋——杨其国
the pioneer of science and technolgy——Yang Qiguo
联合动力：并网先锋
united power: grid-connect pioneer