19.小红带了64元钱,每本练习本3元,他最多可以买( )本练习本.
A. | 20 | B. | 21 | C. | 22 |
15.一堆沙子有$\frac{4}{5}$吨,用去它的$\frac{1}{5}$后,还剩下多少吨?正确算式是( )
0 154952 154960 154966 154970 154976 154978 154982 154988 154990 154996 155002 155006 155008 155012 155018 155020 155026 155030 155032 155036 155038 155042 155044 155046 155047 155048 155050 155051 155052 155054 155056 155060 155062 155066 155068 155072 155078 155080 155086 155090 155092 155096 155102 155108 155110 155116 155120 155122 155128 155132 155138 155146 199269
A. | $\frac{4}{5}$-$\frac{1}{5}$ | B. | $\frac{4}{5}$×$\frac{1}{5}$ | C. | $\frac{4}{5}$-$\frac{4}{5}$×$\frac{1}{5}$ | D. | $\frac{4}{5}$÷$\frac{1}{5}$ |