2.把上层书的$\frac{1}{5}$放到下层书架,则上、下两层书架本数相等,原来下层书是上层书的( )
0 132938 132946 132952 132956 132962 132964 132968 132974 132976 132982 132988 132992 132994 132998 133004 133006 133012 133016 133018 133022 133024 133028 133030 133032 133033 133034 133036 133037 133038 133040 133042 133046 133048 133052 133054 133058 133064 133066 133072 133076 133078 133082 133088 133094 133096 133102 133106 133108 133114 133118 133124 133132 199269
| A. | $\frac{3}{5}$ | B. | $\frac{4}{5}$ | C. | $\frac{1}{5}$ |