（1）If什么时候意思表示“是否”?
（2）L didn’t know.Where will he go
= L didn’t know Where he would go .
为什么用would?
（3）Here is _____ order ,All of you must obey it.
(4) We watch the opening ceremong pf the World Expo on TV ______ last night.
(5)TOM would go to vist his grandparnts if he had free time on Sunday.
为什么用would?
(6) Have you ever been in a maglev tarin
为什么用in