下面是一封代理公司写给外国供货商的访华邀请信，请根据内容填空

题目描述

　　下面是一封代理公司写给外国供货商的访华邀请信，请根据内容填空。　　Dear Mr.Grier：　　We have made extensive______(1)______for the market potential of your thermal processing systems in China and now we are glad to______(2)______you that several customers have shown strong______(3)______in them，particularly the new modeI_ZL387.　　Thev seem to be______(4)______with the introduction in your brochure.but woukl like to have a better understanding of the technical operation of the systems　　We are glad.therefore.to invite and warmly______(5)______you to visit China in this autunm for technical presentation and commercial negotiation.Your visit may______(6)______10 days，covering Beijing，Dalian，Wuhan and Zigong　　Please let us know whether you can______(7)______the trip so that we can make necessary arrangements　　Best regards.