第29题: [单项选择]What is the passage mainly about A. Several worldwide economic problems. B. The causes and consequences of trade deficit. C. Lack of resources in underdeveloped countries. D. The value of exports against imports. 参考答案:B 答案解析:[精解] 题干问的是文章的主题。文章的第一段阐述了引起贸易逆差的因素,第二段阐述了贸易逆差产生的后果,因此答案为B。