_____  inviting me to your party. I'm sure to come on time.[ ]

A. Thanks for            

B. Thanks to

C. Without                

D. Because

降低风阻的措施有（）。

A.扩大巷道断面

B.降低巷道壁的粗糙度

C.改变巷道断面形状

D.调节风窗