2.baby-babies
3.child-children
4.green leaf-green leaves
5.old lady-old ladies
6.radio-radios
7.ox-oxen
8.tall woman-tall women
9.knife-knives
10.toy- toys
11.policeman-policemen
12.raspberry-raspberries
13.sandwich-sandwiches
14.mouse-mice
15.photo-photos
16.cliff-cliffs
17.pen-pens
18.watch-watches
19.big foot-big feet
20.nice book-nice books