已知x=2,y=1与x=3,y=3是关于二元一次方程y=kx+b的解，则k,b的值分别是

                                                                                                                                                        [ ]

A、k=1,b=2          

B、k=2,b=－3

C、k=0,b=－1        

D、k=1,b=－2

简述随车机械师岗位职责？