断面面积均为A=0.48m2的正方形管道、宽高比为3的矩形管道和圆形管道,各自的水力半径分别为()。 ["R正=0.174、R矩=0.15、R圆=0.195","R正=0.15、R矩=0.174、R圆=0.195","R正=0.1、R矩=0.5、R圆=0.5","R正=0.195、R矩=0.15、R圆=0.174"]
简述域名与传统知识产权的异同点。
边缘过重,中心发展时()。 ["风口易灌渣","风口易涌渣","风口与正常时一样","风口易烧坏"]
通过分析儿童的绘画、日记等了解儿童心理的方法是()。 ["实验法","测验法","观察法","作品分析法"]
切分轧制中,导辊契形角越小,轴承载荷分力也就()。 ["越大","越小","两者无关"]
网络参数