How many companies are estimated to take part in the expo?

With first China International Import Expo around the corner,volunteers,after finishing their training began working on a trial operation since Tuesday.Yang Yu is one of them.According to Yang,the group members have to get up before dawn to take a two-hour bus ride to work,as the school is far from the expo venue,and go back to school at around 8 p.m.after working all the day.However,everyone is determined to work their best.The expo,scheduled for November 5-10 in Shanghai,will see the participation of over 130 countries and regions,and more than 2,800 companies.