【简答题】(12分)一个体重50kg的健康人,体内约含有2g铁,这2g铁在人体内不是以单质的形式存在,而是以Fe 2+ 和Fe 3+ 的形式存在。正二价铁离子易被吸收,给贫血者补充铁时,应给予含Fe 2+ 的亚铁盐,如硫酸亚铁。服用维生素C,可将食物中的Fe 3+ 转变成Fe 2+ ,有利于人体吸收。 ①在人体中进行下列转化时, ,①中的 Fe 2+ 作 剂。 ②“服用维生素C,可将食物中的Fe 3+ 转...
【单选题】____ we went those days when we were in the countryside, we were warmly welcomed.
【单选题】We didn’t know you were in trouble at that time, ________we would have given you a hand.
【单选题】We got lost in the forest and decided to remain _____ we were and waited for rescue.
【单选题】The last time we had great fun was________ we were visiting the Water Park. [ ]
【单选题】We were not sure whether they _______ more vegetables.
【单选题】________ we were out of the traffic jam we were able to resume our normal speed.
【单选题】We are going for a picnic tomorrow. I'll call Wendy to make sure ________. [ ]