999×81的值是( )
A.80000
B.71719
C.80919
D.81819
参考答案:C
His uncle ______ for more than 9 years.[ ]
A. has come here
B. has started to work
C. has lived there
D. has left the university
无线射频识别技术的英文缩写为( )。
A.PTL
B.RF
C.RFID
D.EAS