1- I’ll finish doing my homework soon.
2- Does she live in the basement or on the ground floor?
3- Who left the windows open?
4- I will take my kids to the amusement park tomorrow.
5- My grandparent’s old clothes are in the attic.
6- Where will you start working when you finish your English course?
"3 - Who left the window open?"Singular, uma só janela.