阅读下列短文，从每题所给的四个选项（a、b、c和d）中，选出最佳选项。《天津市蓟县二中2014
高考英语模拟
试题》a the world health organization and several other united nations agencies are calling for a major new effort to fight malaria, tuberculosis and aids. these three infectious diseases killed almost 6 million people last
