Scientists observe ___ making the most of our senses when we are young can keep us healthy later on in life.

A．if

B．what

C．that

D．When

若明确营养性缺铁性贫血诊断，应给予的治疗是

A．仅给予饮食治疗

B．口服铁剂叶酸

C．肌注维生素Bl2

D．输血治疗

E．铁剂治疗，若合并心功能不全可少量缓慢输入浓缩红细胞治疗