18. You had us cut your hair because it is too long. A) Your long hair needs cutting. B) You had your long hair cut by us C) Your long hair should be cut. D) All are correct. 19. They had to make plans for extra places in schools in the 1990s. A) Extra places in schools had to be made plans in the 1990s. B) Extra places in schools in the 1990s had to make plans C) Extra places in schools were had to make plans in the 1990s D) Extra places in the 1990s in schools had to make plans 20. I think Alfred Nobel invented dynamite. A) It is think that Alfred Nobel invented dynamite. B) It is thought that Alfred Nobel invented dynamite. C) Alfred Nobel was invented dynamite by me. D) Alfred Nobel was thought to invent dynamite by me. 21. People thought at first that the Crown Prince had been attacked. A) People were thought at first that the Crown Prince had been attacked. B) It was thought at first that the Crown Prince had been attacked. C) People are thought at first that the Crown Prince had been attacked. D) It is thought at first that the Crown Prince had been attacked. 22. People consider that his speech was one of the best. A) It was considered that his speech was one of the best. B) People are considered that his speech was one of the best. C) It is considered that his speech was one of the best. D) People were considered that his speech was one of the best. 23. Police reported that a man had been helping them with their investigation. A) Police reported that a man had been being helped with their investigation by them. B) Police was reported that they had been being helped with their investigation by a man. C) Police reported that they had been helped with their investigation by a man. D) Police reported that their investigation had been being helped by a man. 24. People believed that somebody murdered Miss. Stone. A) It is said that Miss. Stone was murdered. B) It were said that Miss. Stone was murdered. C) It was believed that Miss. Stone was murdered. D) People believed that Miss. Stone murdered 25. People think that an apple a day is good for you. A) It is thought that an apple a day is good for you. B) It was thought that an apple a day is good for you. C) They are thought that an apple a day is good for you. D) They thought that an apple a day is good for you.

`sqrt(21+12sqrt(3))-sqrt(13-4sqrt(3)` Không viết bằng latex viết bình thường nhưng k thêm dấu latex

Dựa vào những từ cho trước, viết thành câu hoàn chỉnh:

Các bạn ơi hôm nay sinh nhật em gái mình mình mong các bạn vẽ giúp mình một chiếc bánh kem có công chúa elsa nhé và tô màu nhé mình sẽ vote 5 * cho ctlhn nhé

Thực hiện phép tính sau: $a,$ $($ $xy$ $+$ $y^{2}$ $-$ $y$ $)$ $:$ $\frac{x^2+xy-x}{x-y}$ $b,$ $\frac{x^3y+xy^3}{x^4y}$ $:$ $($ $x^2$ $+$ $y^2$ $)$

1. What time/ Nga/ get/ morning . 2. when/ it/ hot/ we/ often/ go/ swim ?

Phân tích các đa thức sau thành nhân tử: A = ($x^{2}$ +x+1) $^{2}$ -3( $x^{2}$ +x) -7 B = (x-7) (x-5) (x-4) (x-2) -72 C = ( $x^{2}$ +6x+8) ( $x^{2}$ +8x+15) -24 D = ( $x^{2}$ +5x+6) ( $x^{2}$ -15x+56) -144

làm giúp mình vs ạ tím txđ bài này

Mọi ng giúp em câu này: 128 và 2 mũ 8

Phân tích các đa thức sau thành nhân tử: 4x ²( x - y ) + 9y ²( y - x )