问题 解答题 口算:21×412×3040×2201升=( )毫升210×4120×3050×607000毫升=( )升. 答案 21×4=84,12×30=360,40×220=8800,1升=1000毫升,210×4=840,120×30=3600,50×60=3000,7000毫升=7升.