Vì sao phương trình: ax 2 + bx+c = 0 có hệ số a, c trái dấu thì phương trình luôn có nghiệm a/ 3x 2 - x -8 =0 b/ 2004 x 2 +2x - 1185 =0 d/ 2020 x 2 +5x - m 2 =0 giải giúp nha

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Trang1/2 Trang 1 / 2Bài 1 – Sử dụng dạng đúng của động từ trong ngoặc để hoàn thành các câusau.1. I ……………. (dream) of winning a medal for a long time.2. She …………. (not/ see) much of Vietnam, so she wants to see more thisyear.3. …………..you ever …………… (be) to a desert? No, never.4. Van ……………….. (throw) a surprise party for her boyfriend.5. Where …………….. Stephen …………….. (be) for the past 2 days?6. ……….(You/ take)………… many photographs?7. He (eat)………………. at the King Power Hotel yet?8. They (live) ………….here all their life..9. How many bottles……… the milkman (leave) …….? He (leave) ……….six.10. I (buy)…………. a new carpet. Come and look at it.11. She (write)………….. three books about her wild life.12. We (finish) ……………………one English course.13. My father (not/ play)……….. any sport since last year.14. Some people (attend).............the meeting right now.15. I’d better have a shower. I (not/have)……………………one since Thursday.16. I don’t live with my family now and we (not/see)……each other for fiveyears.17. Where is your mother? She...........................(have) dinner in the kitchen.18. Why are all these people here? What (happen)................................?19. I……….just (realize)……... that there are only four weeks to the end ofterm.20. She (finish) ... reading two books this week. 21. At present, he (compose)........................a piece of music.22. We (have)........................dinner in a restaurant right now.Bài 2 – Gạch chân dưới đáp án đúng.23. His family hasn’t contacted/ didn’t contact him for 5 years.24. She has seen/ saw that movie more than 5 times.25. Stop complaining! You haven’t stopped/ stopped since you arrived.26. We haven’t found/ didn’t find any sign of life since we landed on Mars.27. Ms. Rose has never taken/ has taken never me to see her flat.28. Congratulations! You have passed/ passed the exam.Bài 3 – Khoanh tròn vào đáp án đúng.29. My granny _______________ that detective novel. Trang 2 / 2A. has already read B. has yet read C. readed D. is reading30. There _______________ a lot of changes in Vietnam since the 1990s.A. was B. have been C. has been D. are31. It _______________ him almost 1 hour to go to school by bus every day.A. takes B. took C. has taking D. is taking32. Her hometown _______________ a lot of hills and mountains.A. has B. gets C. is D. has got33. My dog _______________ my cat since I came home.A. is chasing B. has chased C. chased D. chases34. I fell asleep while I _______________ my homework last night.A. was doing B. have done C. did D. is doingBài 4. Mỗi câu sau chứa một lỗi sai. Tìm và sửa chúng.35. I has just decided to start working next week.…………………………………………………………..…………….……..36. He has been at his computer since seven hours.………………………………………………………….………..…………..37. She hasn’t received any good news since a long time.……………………………………………………………..………..………..38.My father hasn’t played any sport for last year.………………………………………………………………..…..…………..39. I’d better have a shower. I hasn’t had one since Thursday.…………………………………………………………….….……..………..40. The lesson haven’t started yet.………………………………………………………….……………………. Tìm trong tài liệu BI_TP_ANH_7_LN_3_%281.4%29.docx Trang 1 / 2