分类：教育/科学-外语学习
问题：英语选择160516.Ironhasanimportantrol 
16. Iron has an important role to play in the _____working of the human body and is val (至关要的) to healthy living.     A) efficient             B) favorite          C) primary        D) current5. He might as well have picked a family _____out of the telephone book a16. Iron has an important role to play in the _____working of the human body and is val (至关要的) to healthy living.     A) efficient             B) favorite          C) primary        D) current5. He might as well have picked a family _____out of the telephone book and stayed with them.     A) at random           B) at a time          C) after all        D) 
回答：C. primary
A. at random