A.6:00 B.12:00 C.0:00 D.18:00
A.上承式T形梁 B.箱梁預應(yīng)力結(jié)構(gòu) C.上承式T形梁和箱梁預應(yīng)力結(jié)構(gòu) D.下承式脊梁
A.22 B.25 C.28 D.30