形成空壳状的铸造桥体厚度一般为()。
A.0.5~0.9mm
B.1.0~1.5mm
C.1.6~1.9mm
D.2.0~2.5mm
E.2.6~3.0mm
参考答案:B
If the weather had been better, we could have had a picnic. But it ____ all day.
A.rains
B.rained
C.has rained
D.is raining
土方边坡坡度大小一般情况下与( )无关。
A.开挖深度
B.开挖方法
C.坡顶荷载
D.开挖机械