题目

已知a∈R，函数f(x)=sin2xcosx-a(x∈R)是奇函数，则实数a的值是A.-1                    B.1                   C.2                   D.0 答案：答案：D  若f(x)是奇函数,则f(x)=-f(-x),f(0)=-f(0),∴f(0)=0,∴0=0-a,∴a=0.Having broken the traffic rules, Tom _____from driving for a year.A．has bannedB．had bannedC．is being bannedD．has been banned