第17题: [单项选择]对承受竖向荷载的钢筋混凝土预制桩,下列最有可能对主筋设置起控制作用的是( )。 A. 桩顶竖向荷载 B. 桩侧阻力 C. 沉桩时土的动阻力 D. 起吊或运输时形成的弯矩 参考答案:D 答案解析:混凝土抗拉性能差,抗压性能好,混凝土预制桩的配筋能帮助桩承受竖向荷载,但更主要的是抵抗起吊或运输时形成的弯矩。
第23题: [单项选择]人的自然生物钟节律周期是() A. 22小时 B. 23小时 C. 24小时 D. 25小时 E. 26小时 参考答案:D
第24题: [单项选择]A. It was interesting. B. It was boring. C. It was discouraging. D. It was moving. 参考答案:D 答案解析:[解析] M:I was deeply affected by the talk the blind boy gave this morning. W:I think everyone