________ by his impressive performance, Peter will probably be accepted by a key university.[     ]

A．To judge  

B．Being judged

C．Judged  

D．Judging

估测天平游码的质量

①观察并读出天平横梁标尺上的最大刻度值为a（g）；

②测得天平横梁标尺上从0到a刻度线之间的距离为b（mm）．

③测得天平左、右两臂的长均为c（mm）．

由以上数据，可估算出该游码的质量为______（g）．