设a=3x2﹣x+1，b=2x2+x，则（ ）                          

设a=3x²﹣x+1，b=2x²+x，则（　　）                                                     

A．a＞b                       B．a＜b                       C．a≥b                         D．a≤b

C【考点】不等式比较大小．                                                                   

【专题】计算题；不等式．                                                                     

【分析】作差法化简a﹣b=x²﹣2x+1=（x﹣1）²≥0．                                       

【解答】解：∵a=3x²﹣x+1，b=2x²+x，                                                  

∴a﹣b=x²﹣2x+1=（x﹣1）²≥0，                                                             

∴a≥b，                                                                                             

故选：C．                                                                                         

【点评】本题考查了作差法比较两个数的大小的应用．