发展浓缩饲料有何意义？如何正确合理地开发和使用浓缩饲料？

A neighbor that has met the feasibility condition
B. A neighbor that has met the feasibility condition and has the lowest cost path towards the destination
C. Any neighbor that is in the path towards the destination.
D. Any neighbor that is in the path towards the destination and whose reported distance equals thefeasible distance

A. 砂砾土
B. 粘性土
C. 砂性土
D. 粘性土和砂性土