5-2+____=____
下列有关Na2CO3和NaHCO3性质的比较中,正确的是( )
植物的根能够不断地生长,是由于
小宇寒假去世贸商城游玩,乘坐室外观光电梯,在电梯匀速上升的过程中
—Do you mind my opening the window to let the fresh air in?—__________. I also would like to breathe in some fresh air.