Переведите и заменитель единственное число на множественное.1.That was a cowboy2.Mary found

Переведите и заменитель единственное число на множественное.
1.That was a cowboy
2.Mary found a flight to Delhi
3.Robert мейд this bookshelf himself
4.The window and the door are closed
5.There is a mouse in the kitchen
6.It is a white goose
7.That wad not a sheep. That was a donkey
8.It is not an interesting story
9.Is that Eric's knife?
10.There was a beautiful bright star in sky
11.It was not the selected song
12.Is that a studious pupil?