A.略有升高 B.升高2倍 C.降低3倍 D.升高3倍
A.5 B.9 C.16 D.20
A.2.5 B.2.3 C.2.1 D.2.0
(A)决定杆塔承受的水平荷载的档距 (B)决定杆塔承受风压的档距 (C)决定杆塔承受导、地线自重、冰重的档距
A.8m B.10m C.12m D.5m