Efficient power flow is calculated by means of tree technique and recursion, which do not need resistance or admittance matrix.
运用树的遍历技术进行实用潮流计算，递归方程的使用使得编程简单，并且不需要形成阻抗阵或导纳阵。
2
According to the flame retardancy of bark and the fire resistance of the 5 tree species, we commended forest fire protection measures correspondingly.
根据5种树皮的阻燃性和林木耐火性差异提出相应的森林消防措施。
3
In the tree and reed, when the wind comes, and trees and reed and powerless to fight, the tree chose high rise, stout resistance, but still won't stand a dull color. gives.