【单选题】The question is so difficult that ______ students can answer it.
【简答题】煅烧石灰石时,温度控制在 1100 °C 左右获得的石灰称为 ,它具有晶粒小、气孔率高、体积密度小、反应能力高等特点。
【单选题】This is _______ difficult problem that few students can work it out.
【单选题】能引起小儿急性肾衰竭最常见的原因是( )
【多选题】成本控制按成本发生的时期不同,可分为( )。
【单选题】The maths problem is too difficult. ______ students can work it out. [ ]
【单选题】力系简化时若取不同的简化中心,则( )。