when did the Shaghai World Expo begin?

when did the Shaghai World Expo begin? when did the accident happen when did the dinosaurs live? When did the children come? When did the earthquake of Wenchuan happen when did the world war break out? When did the accident ( ) ( ) (发生）?填空 when did you take the medicine last when did the Iraqi War break out ? When did they arrive ( ) the airport 翻译 When did the last dinosaurs live? when did you arrive.the museum? When did you_______( 到达)at the airport. when did the play put on when did the story take place?为什么要用did When did the girl finish the homework?中文 翻译,when did the keeoer ask the passengers questions? when did the accident happen?怎麼回答?