單項(xiàng)選擇題單導(dǎo)梁組安裝時(shí),各節(jié)點(diǎn)應(yīng)連接牢固,在橋跨中推進(jìn)時(shí),懸臂部分不得超過已拼好導(dǎo)梁全長(zhǎng)度的()

A.1/2
B.1/3
C.1/4
D.1/4