Let's help them clean the street.(改为一般疑问句）改为一般疑问句!_______help them clean the street?

Let's help them clean the street.(改为一般疑问句）改为一般疑问句!_______help them clean the street?
Let's help them clean the street.(改为一般疑问句）
改为一般疑问句!
_______help them clean the street?

Let's help them clean the street.(改为一般疑问句）改为一般疑问句!_______help them clean the street?
Could we help them clean the street?
我们帮他们打扫街道好吗?