5句改句子,会的帮忙下.

Is English spoken by many people?(主动语态)
Do many people speak English?
The building was built in 2001.(对斜体部分提问)
When was the building built?
We shall discuss the plan next week.(被动语态)
The plan shall be discussed by us next week.
Did you write the letter last night?(被动语态)
Was the letter written by you last night?
About one hundred stamps have been collected.(对斜体部分提问)
How many stamps have been collected?