Instructions:
??12??????????,????25????????????????????1-5??
2.??
????????10?,???5?a??????????????????,????????1---5?
3.??
(1)???
????????,?????????????35???,???????????????,?????????????
(2)???
???????????????,???1?,?????,???????????1??????????????????????,??????????????????????,?????????????
(3)???
?????????????????,????????????????????1??????????????,????????????????
|