赞题库-背景图
单项选择题

结合除涝的田间排水沟,当农沟深度1.5m-2m时,间距一般为()
A.50-150m
B.100-200m
C.150-250m
D.200-300m

A.5m-2m时,间距一般为()
A.50-150m
B.100-200m
C.150-250m
D.200-300m