在自动舵表达式δ=-K1Φ中,系数K1可根据()来选择调节。
A.气候条件
B.舵的类型
C.船型、海况、装载量
D.外界干扰情况
参考答案:C
It ____ that all the students were having lessons in the teaching buildings when the earthquake occurred.[ ]
A. happens
B. was happened
C. happened
D. was happening
对纵向长度较大的混凝土结构,规定在一定间距设置变形缝,原因是()。
A、防止温度变形而产生的结构变化
B、防止混凝土干缩而导致的结构破坏
C、防止基础沉降不均而导致结构破坏