（1）There is a bridge over the river.
There are some bridges over the rivers.
(2) is there a harbor in your city?
Are there any harbors in your cities?
(3) There was a factory in our town.
There were many factories in our towns.
(4) Was there an orange in the bag?
Were there any oranges in the bags?
(5) There is an apple in my hand.
There are some apples in our hands.