11. The universe _______ and has been so since its beginning. A. expands B. expanding C. is expanding D. Expand 12. My sister _______ at home at the moment. A. is staying B. stays C. are staying D. stay 13. Gordon? I think he _______ a letter at the moment. A. writing B. is writing C. are writing D. writes 14. Our teacher always _______ us a lot of homework. A. is giving B. give C. gives D. are giving 15. She_______ a new ruler yesterday. A. didn’t buy B. doesn’t bought C. did buy D. didn’t bought 16. He _______ with his parents about his vacation in Da Lat last year. A. don’t talk B. doesn’t talked C. didn’t talk D. talks 17. They_______ school yesterday. A. didn’t comed B. didn’t come C. doesn’t comed D. doesn’t come 18. The windows _______ yesterday. A. didn’t close B. didn’t closed C. doesn’t closed D. doesn’t close 19. We _______at home at 7 p.m. last Monday. A. didn’t return B. didn’t returned C. doesn’t return D. doesn’t returned 20. She _______fish and crab yesterday. A. doesn’t eat B. doesn’t eated C. didn’t eat D. didn’t ate 21. Lan _______ Ho Chi Minh city two years ago. A. didn’t go B. doesn’t went C. didn’t went D. doesn’t go 22. My parents _______to Vung Tau last week. A. don’t taked B. don’t took C.didn’t take D. didn’t takes 23. We _______a lot of friends in Ha Noi two years ago. A. don’t have B. don’t has C.didn’t had D. didn’t have 24. _______ Lan and Hoa your classmates two years ago? A. Are B. Is C. Was D. Were 25. What_______they _______last week? A. do/ play B. did/ play C. do/ played D. did/ played 26. What _______ Hoa _______ on yesterday? A. did/ try B. do/ try C. did/ tryed D. do/ tried 27. Who _______ about the film on TV last Monday? A. talk B. talks C. talked D. talking 28.Where_______they _______on their way back last Sunday? A. did/ stop B. do/ stop C. did/ stopped D. do/ stopped 29. What _______the student _______at school two years ago? A. did/wears B. did/wear C. do/wears D. does/wear 30. Where _______ you _______ the cake yesterday? A. was/ put B. were/ put C. did/ put D. do/ put 31. What time _______ you _______ home for school yesterday? A. was/ leave B. were/ leave C. did/ leave D. do/ leave

Tìm gtln, glnn của $\sqrt[]{1-x}$ $+$ $\sqrt[]{y-x}$

,..............................

Tính: $(3+$$\sqrt[]{5})($ $\sqrt[]{10}-$ $\sqrt[]{2})$$\sqrt[]{3-\sqrt[]{5} }$

Giải thích ra giúp mình nhá. Giúp mình vs ja. Mình đang gấp Lắm. Mình hứa sẽ tim và vote 5* đầy đủ ạ. Ctlhn cho bạn nào nhanh nhất ạ

1. Kathy usually _______ in front of the window during the class. A. sits B. sitting C. sit D. is sit 2. Rice _______ in cold climate. A. isn't grow B. don't grow C. aren't grow D. doesn't grow 3. Hurry up! We _______ for you! A. waiting B. are waiting C. wait D. waits 4. - What are you _______? - I _______ letters. A. doing/ write B. done/ am writing C. doing/ am writing D. do/ write 5. He _______ in Italy at the moment. A. works B. working C. is working D. work 6. My father _______ excuses when I feel like going to the cinema. A. make always B. do make always C. always do make D. always makes 7. Danny _______ his father every Sunday. A. phones B. is phoning C. phoning D. phone 8. Barbara usually _______ dinner for her husband after work. A. cooks B. cook C. are cooking D. cooking 9. Now I _______ for the shops to open. A. wait B. waiting C. am waiting D. waits

3+ √3 phần 1+ √3 + 1 phần √3-2

Giúp mình làm với ạ mình cần gấp

Bài 2 (1 điểm) Cho phương trình x² + 6x + 6= 0 có hai nghiệm là x1; X2. Không giải phương trình hãy tính A=(√x₁ √x₂)² + x₂² + 2x1x2 - 6x1

mọi người ơi giúp mk câu này với . đạo hàm của hàm số : y = x / căn a bình phương - x bình phương ( a là hằng số )