【单选题】在液相色谱中,改变洗脱液极性的作用是( )
【单选题】在试算平衡表上,虽然实现了期初余额、本期发生额和期末余额三栏的恒等关系,但仍然不能保证账户记录是完全正确的。( )
【单选题】we had hardly got to the station ( )it began to rain.
【单选题】We had hardly got to the school it began to rain.
【单选题】Hardly ____ into the country ____ it began to rain.
【单选题】Hardly had we got to the station_______the train left.
【单选题】Hardly had we got on the bus __ it began to rain.