Where does the rain come from?[ ]

A. It comes from the clouds.

B. It comes from the vapour.

C. It comes from the water.

D. It comes from the water in the river.

上述哪种呼吸方式适用于胸椎摄影（）。

A．平静呼吸不屏气 

B．平静呼吸下屏气 

C．深吸气后屏气 

D．深呼气后屏气 

E．缓慢连续浅呼吸