单项选择题
A、R≤1000m B、R≤1200m C、R≥1200m D、R=1200~4000m
A、4.0 B、4.5 C、5.0 D、5.5
A.R≤1000m B.R≤1200m C.R≥1200m D.R=1200~4000m
A.200 B.100 C.300 D.500
微信扫一扫,加关注免费搜题