【判断题】在数据库编程中,数据库连接池中的连接是用之不完,取之不尽的。
【简答题】已知某钢筋混凝土梁的计算跨度L0=6m,截面尺寸b×h=200mm×500mm,混凝土自重为25KN/m3,则该梁有自重引起的线荷载的标准值为
【简答题】精密称取复方黄连素片粉末4.7306g,置索氏提取器中,用盐酸-甲醇(1:100)液提取至无色,移入100ml容量瓶中,加乙醇至刻度,摇匀。照柱层析法,精密量取10m1置氧化铝层析柱上,用30ml乙醇洗脱。收集洗脱液,置50ml量瓶中加乙醇至刻度,摇匀。精密量取5 m1 ,置10m1量瓶中加水至刻度,摇匀,照分光光度法,在430nm波长处,以50%乙醇为空白,分别测定盐酸小檗碱50mg/100ml...
【单选题】_______Lisa _______Lucy may go with you because one of them must stay at home to take care of the dog.
【单选题】—May I borrow your pencil, please? —Yes, of course. Here are some and you can take ________ of them.
【单选题】----May I borrow your pen, Mike ? ----Yes, of course. Here are some and you can take ______ of them.