English plural nouns of foreign origin

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• 1. How many strata are there?
• 2. Four hypotheses have been presented so far.
• 3. I am going to sell these two series of stamps.
• 4. For the first time these phenomena were noticed two years ago.
• 5. Too many stimuli at the same time many lead to chaos.
• 6. All the crises is question were caused by inefficient management.
• 7. He has written many excellent analyses for us.
• 8. Some species can be found in the zoological gardens only.
• 9. The data collected by you are very important for us.
• 10. Are these two radii equal?
• 11. These dies were made by my uncle Sam when he was a prisoner of war.
• 12. We have dealt with these phenomena for a long time.
• 13. bacteria can be seen only through a microscope.
• 14. All these analyses are inadequate.
• 15. Have you ever heard of food produced from algae.