单项选择题
A.2个 B.3个 C.4个 D.5个
A.1:1.2 B.1:1.3 C.1:1.4 D.1:1.5
A.12m简支箱梁 B.22m简支箱梁 C.32m简支箱梁 D.42m简支箱梁
A.70% B.75% C.80% D.85%
微信扫一扫,加关注免费搜题