氨茶碱的主要平喘机制为（）。

A.直接舒张支气管

B.抑制磷酸二酯酶

C.激活鸟苷酸环化酶

D.抑制腺苷酸环化酶

E.促进肾上腺素的释放

 He put it firmly that in no case ____ give in to others on such matters. [    ]

A. he would

B. would he

C. will he

D. he will