邀请朋友参加博览会邀请函用英文怎么写？

给你一篇范例，好好模仿吧。

把他的主题International IT Fair换成vegetable就行了，格式应该差不多。

Investment and exhibition invitation for ITF (International IT Fair) is fully started

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2008-04-07

On the afernoon of April 2, the Fourth China (Jinan) International Information Technology Fair held its first meeting, and stressed that it would intensify efforts to promote ITF publicity. ITF is an international IT fair of China-foreign cooperation and province-ministry building. This ITF will be mainly for four aspects of innovation and product exhibitions, forums for innovative technology applications, project promotions and investment talks and supply and demand meetings for IT talents. Different from the previous ones, the current ITF will be mergered with the Fifth China Exhibition and Trade Fair for Jinan Universities and Colleges, Research Institutes and Scientific and Technologi