If I____ more time, I would come to see him this weekend. A. had B. has C. have D. Have had 19. If I had time, I...........to the beach with you this weekend. A. would go B. will go C. will have gone D. Would have gone 20. Parents should ................. their children carefully to become good citizens of the society. A. education B. educated C. educate D. educating 21. Whales feed on krill. A. tiny shellfish B. small fish C. sea plants D. small animals 22. .................... is the variety of different types of plant and animal life in a particular region. A. Interaction B. Herbicide C. Environment D. Biodiversity 23. ......................is a chemical used for killing- weeds. A. Pesticide B. Herbicide C. Fertilizer D. Antibiotic 24. Sperm whales are ................, which means they eat meat. A. herbivores B. carnivores C. omnivores D. Mammals 25. Sperm whale population are at risk due to hunting. A. in extinction B. in danger C. on the decrease D. In fewness 26. What would Tom do if he ......................... the truth? A. would know B. has know C. knows D. knew 27. You....................Mark. You know it's a secret. A. should tell B. shouldn't tell C. couldn't tell D. might tell 28. ...............you, I would think twice about that decision. It could be a bad move. A. If I am B. Should I be C. Were I D. If I had been 29. 'Would you like some cake?' 'No, thanks. If I .......................... cake, I....................fat.' A. ate/ will get B. ate/ would get C. would eat/ could get D. am eating/ will get 30. If I weren't working for an accounting firm, I ........................ in a bank. A. work B. will work C. have worked D. would be working

Nguyên tố R thuộc nhóm VA trong BTH. Trong hợp chất của nó với hidro có 8,824% H về khối lượng. Công thức với H là A. H2S​ B. H2O​ C. NH3​ D. PH3

Hợp chất khí với hiđro của một nguyên tố có công thức RH2. Trong oxit cao nhất của R chứa 50% khối lượng O. Tên của R là: A. Silic (M=28)​ B. S (M=32)​ C. Oxi (M=16)​ D. Clo (M=35,5)