一些conuntable既問題

Words:
research,pianos,luggage,mice,geese,salmon,wood,aircraft,
plastic,yoghurt,knives,cheese,spaghetti,petrol,lemonade,wine,
silver,equipment,furniture,potatoes,cothing,children,knowledge,
help,love,feet,information,sheep,advice,physics,news,tennis,
mathematics,jewellery,mice

1.What is countable nouns?
These include:
2.The plural ending-s or-es:
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3.The plural not ending in-s:
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4.The nouns having the same form in the singular and the plural:
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