缺铁性贫血患儿应用铁剂治疗，最先出现的血液改变是（）

A.血红蛋白增加

B.皮肤苍白消失

C.网络红细胞增加

D.头晕、乏力症状消失

E.肝、脾恢复正常大小

--- How soon will you start your journey?

--- I'm not sure.  I haven't decided_______.

A．when shall I ask the boss for leave

B．where I will go to spend the holiday

C．if I would go by train or by plane

D．who should I travel with