直线ax﹣2y﹣2a+4=0被圆x2+y2﹣2x﹣8=0所截得弦长范围是（ ）．
[4，6]
—Was it by cutting down staff ________ she saved the firm?
—No，it was by improving work efficiency. (2012·上海，37)
A．when
B．what
C．how
D．that
在混凝土中，凡颗粒大于（）mm的骨料称为粗骨料.
A.3
B.5
C.4
D.6
