When _______ help, one often says “Thank you.” or “It is kind of you “

A．offering

B．to offer

C．to be offered

D．offered

关于用力呼吸的描述，不正确的是（）。

A.呼气时腹壁肌收缩

B.吸气时膈肌收

C.吸气时辅助吸气肌参与收缩

D.呼气时肋间内肌收缩

E.呼气时肋间外肌收缩