the complement of sets

• 集合的补

the complement of sets的用法和样例：

例句

1. When reading he attaches great importance to the epilogue of books.
   他看书时很重视后面的补记。
2. The new system has advantages of stability, Iow cost and economy.
   与传统的补水方式比较，具有性能可靠，运行成本低，节约能源的优点。