【单选题】I'd rather you _____ that.
【单选题】正常物品价格上升导致需求量减少的原因在于
【单选题】It is time that you __home and I'd rather you__ again tomorrow.
【单选题】I'd rather that you ________ home.
【单选题】I'd rather that you ______ tomorrow than today.
【单选题】I'd rather that you ________ home. A. went B. have gone C. will go D. had gone
【简答题】一台抽水机用的电动机的功率为2.8 kW,每天运行6个小时,问一个月(30天)消耗多少电能?
【简答题】用一台功率为40kW的电动机带动水泵抽水,供给高出水面24m的水箱,已知水箱容积为50m 3 ,整个抽水装置的机械效率为60%. 求:(1)水箱充满水后,水箱内水的质量; (2)把空水箱充满水,抽水装置做的总功; (3)需多长时间才能把空水箱注满水.(g取10N/kg)