1 the 41st session of the expo 2010 from May 1 to October 31,held in Shanghai.
2 in order to keep healthy,we participate in regular physical activity.
3 we are expected to complete this project in the weekend.
4 some people didn't go to send their children to school.
5 for I don't know him,although I've known him for a long time.
6.It seems to rain.When you leave the best don't keep the Windows open.