题干
It might have saved me some trouble ______ the schedule.
A：did I know
B：have I known
C： do I know
D：had I known
答案(点此获取答案解析）
D
It might have saved me some trouble ______ the schedule.
A：did I know
B：have I known
C： do I know
D：had I known
3C(g )+D(g ),若反应开始时充入2 molA和1 molB，达到平衡时C的物质的量浓度为amol/L。若维持容器体积和温度不变，按下列四种配比作为起始物质，达到平衡后，C的物质的量的浓度仍然为amol/L的是( )
