有助于减少机体耗氧量的是（）。

A.放松练习

B.腹部加压暗示呼吸法

C.腹部沙袋加压呼吸法

D.缩唇呼气法

E.缓慢呼吸

He said he had been to Hong Kong ____ and he would go there _____ once

again.[      ]

A. long before, before long

B. before long, long before

C. long ago, before long

D. long before, long before