????:1??????????:????????

2????????????

3????????????

4?????+v

5??????????

12????????????28???,???????????????????“??”?????????

??????????,???????,???????,???

??,????????“??”???????6????28?????????,?6?????????,??,?“????”??,?????????,??12kg?

??????,??“??”???????,????????????“?”?“?????????”??,????????????,?????“??”?????????????,“?????????”?????????????,??(??? ???????????)

????????:????????????