读全球经济发展比较快的几个国家轮廓图,据此回答18~20题.
look forward to, accuse sb. of sth., be eager to, inform sb. of sth., concentrate on, so as to, demand to, depend on, assist sb. with sth. ahead of
如图所示,甲、乙、丙、丁是四幅实验装置图,对它们解释错误的是( )