Lập mệnh đề phủ định của mỗi mệnh đề sau : a) P:" ∀n ∈N : n^2 -1 là số lẻ" b) B:" ∀n ∈N : n^2 +1 là số chẵn" c) B:" ∀n ∈N : n^2-2 là số lẻ"

Có 50g dung dịch NaCl 20%. Tính nồng độ % dung dịch thu được khi: a) Pha thêm 20g H2O b) Cô đặc dung dịch để chỉ còn 35g

Choose the correct option A, B, C or D to indicate the sentence that is closets in meaning to each of the following questions. 41. May said, “I have to finish the homework before lunchtime”. * A. May said that she can do the homework before lunchtime B. May said that I have to finish the homework before lunchtime. C. May said that she has to finish the homework before lunchtime. D. May said that she had to finish the homework before lunchtime. 42. He has learned Japanese for 5 years. * A. It was five years ago did he start learning Japanese. B. He started learning Japanese five years ago. C. He hasn’t learnt Japanese for 5 years. D. It is more than five years since he started to learn Japanese. 43. The sound of our voices was completely drowned by the roar of the machinery. * A. The machines were making such a loud noise that we couldn’t hear each other. B. We tried hard to hear each other above the deafening machines. C. We knew that the machines would drown out our conversation, so we didn’t try to speak. D. Because the machines were so deafening, our voices seemed rather fainted. 44. My brother broke my mother’s vase. * A. My mother broke my brother’s vase. B. My mother’s vase was broken by my brother. C. My brother didn’t touch my mother’s vase. D. There is no vase in my house now. 45. It was careless of you to leave the window open last night. * A. You shouldn’t leave the window open all night. B. You are so careless that you left the window open all night. C. You were so careless to have left the windows open last night. D. You might be careless because you left the window open last night.

viết dấu thích hợp vào chỗ chấm ; 234 x (1257-257)=234 1257 234 257

bài này khó quá ai có thể chỉ em với ạ

6/13+ x = 7/6 va 13/5 - x = 5/6

Tóm tắt đoạn hội thoại unit 1 lớp 8 ( đặt part 2) mình mong nó là đoạn văn cơ ạ

vẽ đậu mầm nl avata mình đẹp ko

III. Choose the best answer to complete the following sentences 1. _________he isn’t available, we’ll look for another consultant. A. Unless B. In the case that C. While D. When 2.She presented me with a new blanket on which she beautiful flowers. A. knitted B. embroidered C. moulded D. carved 3.My parents once took me to Bat Trang village. I could make my own _______there. I really enjoyed it. A. pottery B. lacquer C. painting D. sculpture 4. Studies indicate that there are______________ collecting art today than ever before. A. the most people  B. more people C. many people  D. as many people 5. This wall is said ............three hundred years ago. A. to build B. to have been built C. to have built D. to be built 6.This is the first time he_________________ a novel written by an American novelist. A. read B. have read C. has read D. reads 7.In the past, local were chosen to make sophisticated embroidered costumes for the Vietnamese King, Queen and other Royal family members. A.skill workers B.skillfully works C.skillful artists D.skilled artisans 8. Craftsmen have to the domestic and international markets so that they needn't depend on the middlemen for their sales. A. find B. find about C. find out D. find out about 9.Villagers are morekind, friendly and warm-hearted than city . A. dwellers B. foreigners C. beginners D. movers 10.No city in America has monuments and museums into one area as Washington, DC. A. as much B. such many C. as many D. a few 11.The new student was very shy at the beginning, but then he well with everyone. A. got on B. went on C. got over D. cheered up 12.The police never all hope of finding the lost child. A. stops B. think over C. grow up D. give up 13.He'll be very upset if his employer his offer. A. pulls down B. finds out C. turns off D. turns down 14.It's time to say goodbye, but I'm meeting you all again soon. A. looking forward to B. getting on with C. keep up with D. put up with 15. a large number of the country's craft villages are suffering from a shortage of human resources and difficulties in building brand recognition, many international organizations have had projects to help them. A. However B. But C. Even D. Although 16.Nowadays, Tan Chau artisans can produce silk of multiple colours they can meet customers' demands. A. so B. so that C. but D. in order 17. 12. How can we encourage people to get along with each other in this society? a. considerable b. multicultural c. rural d. crashing 18. The department is also deeply in various improvement schemes. A. connected B. entailed C. involved D. implied 19. His answer was so confused that I could hardly make any of it at all. A. interpretation B. meaning C. intelligibility D. sense 20. We are looking for someone who is and hard-working. a. hopeful b.lacked c.reliable d. smooth 21 I wish you’d tell me what I do in this difficult situation. A. shall B. would C. should D. ought 22. 8. Jeans………all over the world. A. are sold B. is sold C. sell D. sold 23. Liz wants to …………a lot of photos to show the trip to her parents. A. make B. take C. reach D. spend 24. The city theatre ____ in 1900. A. built B. was built C. has been built D. will be built 25. They always kept on good with their next-door neighbours for the children’s sake. A. friendship B. relations C. will D.terms MN GIÚP MK VS Ạ , HỨA CHO CTLHN

vẽ phong và sammy cảnh phong bế sam hứa cho 5 sao