英语4句,不是翻译,填空,都很简单

英语4句,不是翻译,填空,都很简单
It's very cold in winter.（变成问句）
( )( )weather in win-ter?
除了：what's the weather in winter"?
shanghai has 13 millon people（变成同意句）
1.( )( )of shanghai ( )13 millon people.
2.shanghai has( )( )( )13 millon people.
our classroom is smaller than theurs.（变成同意句）
( )classroom is ( ) ( )
an elephant,a horse,much,is,than,heavi-er
(连词组句)