G:hello,is it xxx exhibition company?
M:um...yes,i'm the secretary of the company,can i help you?
G:well,i still have some questions about the exhibition?
M:so what question?
G:i don't know when the exhibition start and how long it last.
M:ok,let me check...oh,it begins at 8 am tomorrow and lasts 3 hours..so it lasts until 11am
G:ok,i write it down.
M:if you want more information about it,call me back at any time.
G:thanks
M:you are welcome!