4.According to the author, a wise established manufacturer should ______.

　　A.try to benefit from both financial and technical resources

　　B.break up his partnership with the East once profits are made

　　C:keep a tight told over hi-tech development and marketing of airliners

　　D.collaborate with Asian partners for a short time

　　5.The word “base” in the last paragraph represents_______.

　　A.a production place

　　B.the initial operation of building aircraft

　　C.a research institute

　　D.a position where to start building

　　第二十二篇答案：CDADA