若一元二次方程2x（kx-4）-x2+6=0无实数根，则k的最小整数值是 [ ]
A.-1
B.2
C.3
D.4
答案：B
It was rather strange how the habits of his youth clung to him still. He was 72.
A．stuck to
B．turned
C．led to
D．gave way to
酸雨作为全球性环境问题之一，主要由哪种气体的排放引起？
