因为你根据原文想避免使用主语对吧,所以后面很难理顺了.我想你的主语可能是I 或者We吧,不如把它用上,但不是全用.你看这样行不行：
We accompany sb.to visit the ECO&TECH development district in the Qiandao lake(或者用你原来的说法也可以：））of Chun'an County,to start the WBC promoting discussion,we've visited the area,listened to the leaders'introduction,and started negotiation on the cooperation issues.