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

2?????????

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

4?????????

5?????vx

??9???????????20?? ?,??9????20??10?????

??,9?????20?????14?????????21???14?,????????????????????????????????????????????????????????????????????,????,??????????????????????????????????????(100~150????)?????(????20~50??????,??????????????????60????????????),????????????

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

????:

1???????????????;

2???????,???????;

3??????,??????????????????????????,???????;

4???????????,?????????????????????

??:??