Cho biết có chất sau đây : a) nước do hai nguyên tố là H và O tạo nên . b) axít do 3 nguyên tố là H ,S,O tạo nên c) khí ozon là do nguyên tố oxi tạo nên d) khí cacbonic do 2 nguyên tố tạo nên e) phân đạm amoni sunfat do 4 nguyên tố là N,H,S và O tạo nên Vậy - Nguyên tố oxy tồn tại ở dạng đơn chất trong những chất nào ? - Nguyên tố oxi tồn tại ở dạng hợp chất trong những chất nào ?

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giúp vsssssssssssssssssssssssssssssssssssssssssssssssssssssssss max khó 1. We will give her this gift when we arrive there. => This gift will be____________________________________ 2. They will have the car repaired soon. => They_______________________________________________ 3. Did you happen to run into George last week? => Did ________________________________________________ 4. Kara will turn James down if he asks her to marry him. => Should James_______________________________________ 5. Carrie will finish university, and then she hopes to get a job immediately. =>Carrie would _________________________________________________________ 6. You could not have made a very good impression on them. => It’s___________________________________________________________________ 7. A computer is only as good as the person operating it. => It is importance___________________________________________________ 8. Anyone who goes into politics must be prepared to lie sometimes. => A person going_____________________________________________________ 9. Turkey is capable of producing all of the food that it consumes every day. => Every day the population of _______________________________________ 10. Few people are as mistrusted as politicians. => Politicians are _____________________________________________________ 11. The results of the research ---- that, presently, several East Asian countries ---- rapidly. (indicate/develop) 12. Understandably, her friends ---- when Julia married someone else after being engaged to John for two years. (surprise) 13. The facsimile ---- when the secretary returns from lunch. (send) 14. Because James ---- to physical work, he ---- after he had spent a week on the farm. (not accustome/)exhauste 15. 5. Animals ---- to survive in the wild, rather than kept in captivity. (help)