很显然，先有趋势线，后有轨道线，但是两者同样重要。 ( )
参考答案：错
—Why is it ________ so many people enjoy eating on the run?
—Of course, the most obvious answer is that fast food is fast.
A．that
B．which
C．what
D．how
从铣锥底圆接触套管内壁到底圆刚出套管外壁此段应采用（）
A.轻压慢转
B.中压慢转
C.中压快钻
D.重压快钻
