— You told Holmes about what happened in the train?  

— No,I didn't. He had rushed off towards the station________I could say anything more.   [    ]

A. before        

B. until        

C. when          

D. as

患儿，女，3岁。因反复呼吸道感染和腹泻2年，皮肤湿疹6个月就诊。血IgG低，IgA0.03g／L，IgM正常，唾液中未检到分泌型IgA。

对患儿最危险的治疗是（）

A.输新鲜血液

B.增效联磺片

C.青霉素

D.抗过敏药

E.口服人初乳