英语改句子，求助

We mustn't run across the road.改为祈使句
We must keep quiet in the reading room.  in the reading room 是划线句 对划线句提问

This sign says,   Don't turn left.   Don't turn left 是划线句  对划线句提问

1.Don't run across the road.

2.Where must we keep quiet?

3.What does the sign say?

Don’t  run across the road.

Where we must keep quiet？

What does this sign say？

Don't run across the road.

where should we keep quiet

what does the sign say?