This room's very untidy.请问room后面为什么要加‘s啊?

This room's very untidy.请问room后面为什么要加‘s啊? my room的英语作文怎么写?THANKS!用This is my room,It's very nice!开头 This bedroom's very untidy. this lamb's very good. 1.This is a very small room.= This is ________ _______ ________ room. This room is very small.怎样变为感叹句? 句子填空1.It's very hot in this room .Why don't you____your coat?A.take off B.wear C.put on D.be in It's very cold here in this room.______.A.so it is B.so it does C.so does it D.so is it It's very cold in this room.Why don't you ( ) your coat?A take off B wear C put on D take to This room is Mike's and Tom's This is Mr Green's room.Mr green's画线 this is lily`s and lucy`s room 改错 Tom's room is very ( ) 以d开头 my daughter's room is always very ______.填什么? smith's waiting room is very full today. This piece of music (s )very beautiful. 英语任务性阅读先阅读短文,然后根据题目要求及所给语境完成下列任务（brother,seeing,big,flower,they）This is a picture of twin brothers,Eric and Evan‘s room.It's not big,but it's very clean.It's a nice room.In the room, I like this book very much.it's very i________.