After he had a _____breakfast, he left his home ______ .

A．quick; quick

B．quickly; quickly

C．quickly; quick

D．quick; quickly

建筑桩基变刚度调平设计是指通过调整桩基础的（）从而改变基桩支承刚度分布，使建筑物沉降趋于均匀、承台内力降低的设计方法。（）

A.桩径

B.桩距

C.桩长

D.成桩工艺