單項(xiàng)選擇題梁跨度較大時(shí),為防止?jié)仓炷梁罂缰辛旱紫蛳聯(lián)锨?,中部?yīng)起拱,如設(shè)計(jì)無規(guī)定時(shí),起拱高度為全跨長度的()

A.0.8%~1%
B.1%~3%
C.3%~5%
D.0.1%~0.3%