【单选题】In which situation would you use the following apology? I am sorry if the instructions were not clear.
A.
When you are apologizing for a small error
B.
When you are not sure if the instructions were clear
C.
When you know you wrote unclear instruction
【判断题】汽油发动机点火时间过晚,会使发动机冷却液温度升高。
【简答题】麻雀飞行时的功率约为8W,即1s时间飞行的麻雀做功约 _____ J;飞行5min麻雀做功约 ______ J。
【简答题】在50m深的矿井里,需在5min内把30m 3 积水抽到井上,应该用至少多大功率的水泵抽水?
【单选题】在强夯后的地基上钢管桩施工按相应定额的人工及机械乘以系数( )。
【简答题】皮影客是一款帮助普通快速制作(__)的软件。
【简答题】容量都是2L的电水壶,功率是1kW的,用20min可以将水烧开;而功率是3kW的,只要5min就可以将水烧开。请问哪种电水壶省电?