easy
rebels (исключения)
the V usage
double agents
find the mistake
100

apple

apples 

100

one child, two...

children

100

leaf

leaves

100

one sheep, ten...

sheep

100

I have two potatos. 

Right: potatoes

200

bus

buses

200

one foot, two...

feet

200

knife

knives

200

one fish, five...

fish

200

look at those gooses!

Right: geese

300

fox

foxes

300

one mouse, two...

mice

300

wife

wives

300

one deer, three...

deer

300

I brushed my tooths

Right: teeth

400

church

churches

400

one tooth, two...

teeth

400

be careful: roof 

roofs

400

this series is boring. These...are boring.

series

400

The pianos are haavy

No mistake

500

как правильно написать "платья"?

dresses

500

one ox (бык), two...

oxen

500

be careful: chef

chefs

500

what is the plural of "aircraft"(воздушное судно)?

aircraft

500

Three woman are talking

Right: women