The windows are clean.

窗户是干净的。

同一单元的其他句子

• This is my classroom.这是我的教室。
• The classroom is big and bright.教室又大又明亮。
• We have a blackboard in our classroom.我们教室里有一块黑板。
• How many desks are there in your classroom?你们教室里有多少张课桌？
• There are twenty chairs in the classroom.教室里有二十把椅子。