1.The man under the tree must be Mr Green.（改为否定句）

1.The man under the tree must be Mr Green.（改为否定句）
The man under the tree _________________ Mr Green.
2.Do you know whose bag it is?（改为同义句）
Do you know ________________ the bag ______________?
3.There are some boys who are playing on the playground.（改为同义句）
There are some boys ______________ on the playground.
4.你不知道当时你妈妈有多担心.
You don't know __________________ your mom was at that time.