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

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

3???????vx

4???????

5??????????????

????9???????????12?????????????,???????75???????????50???????????????????,??????????400??????????????????????

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

?(Bruce Ralston)??,???????????????????????????????????,??????

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

???(Don Davies)?????????,????????????????,?????“???????????????”???????????,???????????????????????????

???????????“??”????50???????????

??????1974???????????????(????? ????????????????????????????? ??????????????? ??????????????????????)

???:????