_____ he realized it was too late to return home.

A．No sooner it grew dark than

B．Hardly did it grow dark when

C．It was not until dark that

D．It was until dark that

主要用于预防支气管哮喘的药物是

A．阿托品+毛果芸香碱
B．阿托品+碘解磷定
C．肾上腺素
D．去甲肾上腺素
E．色甘酸钠