b/ |x-9/2| + (x + y +1)^2 + $\leq$ 0

Các câu hỏi liên quan

 Exercise: Choose the best answer: 1. Many young people are fond of -------------- football and other kinds of sports. A. play B. to play C. playing D. played 2. They couldn’t help -------------- when they heard the little boy singing a love song. A. laughing B. to laugh C. laugh D. laughed 3. Your house needs -------------- . A. redecorated B. redecorating C. being redecorated D. to redecorate 4. I remember -------------- them to play in my garden. A. to allow B. allow C. allowing D. allowed 5. It was a nasty memory. Do you remember both of us wearing sunglasses to avoid -------------- by the supervisors? A. to recognize B. to be recognized C. recognizing D. being recognized 6. I can’t bear thinking back of that time. I’d rather ---------- equally. A. treat B. be treated C. have treated D. treating 7. Did you accuse Nam of --------- a plate? Well, I saw him ------ it off the table with his elbow. A. break/ knock B. breaking/ knocking C. to break/ to knock D. breaking/ knock 8. We found it very difficult -------------- with Gamma. A. to work B. work C. working D. worked 9. I can’t read when I am traveling. It makes me -------------- sick. A. feel B. to feel C. felt D. feeling 10. I need -------------- what’s in the letter. Why don’t you let me -------------- it? A. to know/ to read B. know/ read C. to know/ read D. knowing/ read 11. I suggest -------------- some more mathematical puzzles. A. do B. to do C. doing D. done 12. We regret -------------- you that we cannot approve your suggestion. A. inform B. to inform C. informing D. informed 13. The driver stopped -------------- a coffee because he felt sleepy. A. have B. to have C. having D. had 14. Have you ever considered -------------- a pharmacist? A. become B. becoming C. to become D. became 15. You had better -------------- at home until you feel better. A. staying B. stayed C. to stay D. stay 16. I remember -------------- my mother said the grass in the garden needed --------------. A. to hear/cutting B. hear/cut C. heard/to cut D. hearing/ cutting 17. Peter sometimes help his sister --------------. A. do homework B. to do homework C. with homework D. all are correct 18. I would rather -------------- at home than --------------out with you. A. staying/going B. to stay/ to go C. stay/go D. stayed/went 19. I would rather you --------------. A. drive B. to drive C. drove D. driven 20. She didn’t say a word and left the room. A. She left the room without saying a word B. She leaving the room without saying a word C. She left the room saying a word D. She left the room to say a word. 21. My father wanted me -------------- a pilot. A. become B. to become C. becoming D. became 22. Please wait a minute. My boss is busy -------------- something. A. write B. writing C. to write D. to writing 23. My teacher doesn’t allow us --------- while he is explaining the lesson. A. talk B. to talk C. talking D. talked 24. We have plenty of time. We needn’t -------------- A. hurry B. to hurry C. hurrying D. hurried 25. I promised -------------- on time. I mustn’t -------------- late. A. be/be B. to be/to be C. to be/ be D. be/to be 26. Mary and I are looking forward -------------- you. A. of seeing B. for seeing C. to seeing D. to see 27. I’m sure that he knows -------------- this new machine. A. to use B. using C. how using D. how to use 28. Psychiatrists and doctors have failed -------------- people not to drink. A. to tell B. telling C. tell D. told 29. The students are used to -------------- in the school library. A. working B. work C. to work D. worked 30. Our room needs -------------- up. A. tidied B. to tide C. tidy D. tidying 31. Mercury’s low gravity makes you -------------- very light in a spaceship. A. feel B. feeling C. to feel D. felt 32. “ Was the test long?”. “ Yes, John was the only one -------------- it” A. to finish B. finishing C. finished D. finish 33. A lots of needs -------------- to the house before anyone can move in. A. be done B. doing C. to do D. done 34. It is about time you -------------- harder for the next exam. A. worked B. working C. work D. to work 35. If he really doesn’t feel like ------------ now, I suggested that he should go out for some fresh air. A. work B. to work C. worked D. working