A:Who are you?
B:Where are you?
代数式x2-4x+3的最小值是( )
“十面霾伏”成了冬日里的常见现象!相关数据表明,如今在中国每年因为大气污染过早死亡的人数有50万人!下列治理雾霾措施中,不合理的是( )
—Do you have a basketball? —______.