【简答题】A young boy was sitting in the back seat of the car eating an apple. He asked his father, “Why does my apple turn brown?” his father answered, “When the skin is removed, air reaches the flesh of the a...
【简答题】A young boy was sitting in the back seat of the car eating an apple. Hw asked his father, “Why does my apple turn brown?” His father answered,”“When the skin is removed, air reaches the flesh of the a...
【单选题】某十二层现浇钢筋混凝土框架结构,乙类建筑,质量和刚度沿高度分布比较均匀,房屋高度38.4m,抗震设防烈度7度,设计基本加速度为0.1g,设计地震分组为第一组,Ⅱ类场地。结构基本自振周期T 1 =1.1s,周期折减系数为0.65,采用C30级混凝土(f t =1.43N/mm 2 )。箍筋和纵向钢筋分别采用HPB235(Φ,f y =210N/mm 2 )和HRB335( ,f y =300N/mm...