Cho e hỏi chất này có phải là este ko ạ , giải thích vì sao OHCH$_{2}$ CH$_{2}$COOC $_{3}$H $_{4}$

Ở một loài thực vật, A - thân cao trội hoàn toàn so với a - thân thấp; B - hoa đỏ trội hoàn toàn so với b - hoa trắng. Mỗi cặp gen nằm trên 1 cặp NST tương đồng khác nhau. Cho cây thân cao, hoa đỏ dị hợp các cặp gen tự thụ phấn được F1. Cho các nhận định sau đây về F1 (1). Trong số các cây thân cao, hoa đỏ, cây đồng hợp chiếm tỷ lệ 1/9 (2). Tỷ lệ câu mang 1 tính trạng trội chiếm tỷ lệ 37,5% (3). Nếu cho các cây thân cao, hoa đỏ F1 giao phấn với nhau, tỷ lệ đời con mang 2 tính trạng lặn chiếm tỷ lệ 1/81 (4). Trong số các cây thân cao, hoa đỏ tỷ lệ các cây khi tự thụ phấn cho đời con đồng loạt giống nhau chiếm tỷ lệ 1/9 Số khẳng định đúng là 1,2,3 e lm rồi ạ Cần 4 thôi ạ

VII.Combine a clause in column A with a clause in column B to make complex sentences. A 1. Before I have breakfast, 2. They were talking 3. Although he worked very hard, 4. Since Joe has high blood pressure, 5. Never look down on anybody 6. After he finished his homework, 7. When he finished his degree, 8. George was obviously in a bad mood, 9. He’ll be able to maintain a healthy weight 10. Whenever they eat at this restaurant B a. his parents let him play video games. b. Matt got a job in a software company. c. because he didn’t even say good morning. d. unless you’re helping him up. e. they order a hamburger and fries. f. if he keeps exercising. g. he has to watch what he eats. h. he didn’t manage to pass the exam. i. I spend half an hour doing exercises. j. while the teacher was explaining the lesson VIII. Combine each pair of sentences using the conjunction in brackets. 1. The world is getting warmer. Polar bears are in danger of becoming extinct. (because) _______________________________________________________________________ 2. There weren’t enough students. They closed the village school. (as) _______________________________________________________________________ 3. I really enjoyed the concert. The music was too loud. (although) _______________________________________________________________________ 4. He got a creampie smashed in his face. Everyone laughed. (when) _______________________________________________________________________ 5. Paul was walking to the bus stop. He found somebody’s wallet on the ground. (while) _______________________________________________________________________ 6. Jackie will take out the trash. She is done with her chores. (after) _______________________________________________________________________ 7. You study for the test. You will do much better. (if) _______________________________________________________________________ 8. Rex practiced his guitar. He could play the song perfectly. (until) _______________________________________________________________________ 9. We could get back to shore. It started to rain hard. (before) _______________________________________________________________________ 10. I saw him. He was always carrying a plastic shopping bag. (whenever) ______________________________________________________________________

Trên tia Ox vẽ ba đoạn thẳng,OA,OB,OC sao cho OA =3 cm ,OB bằng 5cm OC bằng 7 cm.Chọn khẳng định đúng: A.BC>BA B.BC bằng BA C. BC < BA Nhớ giải thích sao chọn nha:)

Tìm x: x^5 + x^4 + x^3 + x^2 + x +1= 0

1:Làm tính chia: (2x^4 + x^3 – 5x^2 – 3x - 3) : (x^2 – 3) 2: Cho x, y là 2 số khác nhau thoả mãn x^2 – y = y^2 – x. Tính giá trị của biểu thức A = x^3 + y^3 + 3xy(x^2 + y^2) + 6x^2y^2(x + y). giúpppppppp

Cho mik hỏi hai góc đồng vị có số đo là bn ạ

Give right word formation of these following words 1. Will you please give us some ..................... explanation? (far) 2. You should ........................ yourselves with the new environment. (family) 3. She likes going ............. with her classmates. (picnic) 4. Are there any................... between them? (similar) 5. There're many................... programs at the Festival in Hue (culture) 6. Although some societies are ................... undeveloped, their languages are very complex (technology) 7. It's education that helps with the ................... of knowledge for the young (rich) 8. He likes watching...................programs on TV (entertain) 9. Many...................say that is the best method to adopt (science) 10. Esperanto, however, proves to be useless because It's ................... (popular) 11. The man could give no................... for his violent behavior (explain) 12. I know all the boys who live in my...................(neighbour) 13. He does not agree with the...................that there is life on other planets (believe) 14. A letter should always end with the ...................of the writer. 15. There is a great...................between Hari and his twin brother (similar)

Có ai giải thích vì sao chọn đáp án đấy được không! Em cảm ơn

One major advantage with the use of renewable energy is that as it is renewable it is therefore sustainable and so will never run out. Renewable energy facilities generally require less maintenance than traditional generators. Their fuel being derived from natural and available resources reduces the costs of operation. Even more importantly, renewable energy produces little or no waste products such as carbon dioxide or other chemical pollutants, so has minimal impact on the environment. It is easy to recognize the environmental advantages of utilizing the alternative and renewable forms of energy but we must also be aware of the disadvantages. One disadvantage with renewable energy is that it is difficult to generate the quantities of electricity that are as large as those produced by traditional fossil fuel generators. This may mean that we need to reduce the amount of energy we use or simply build more energy facilities. It also indicates that the best solution to our energy problems may be to have a balance of many different power sources. Another disadvantage of renewable energy sources is the reliability of supply. Renewable energy often relies on the weather for its source of power. Hydro generators need rain to fill dams to supply flowing water. Wind turbines need wind to turn the blades, and solar collectors need clear skies and sunshine to collect heat and make electricity. When these resources are unavailable so is the capacity to make energy from them. This can be unpredictable and inconsistent. The current cost of renewable energy technology is also far in excess of traditional fossil fuel generation. This is because it is a new technology and as such has extremely large capital cost. 1. what is the most important advantage of renewable resources? 2. which is less expensive to operate, non-renewable or renewable energy?why? 3. what does wind energy need to generate power 4. why is the total cost of renewable energy technology far more than that of fossil fuels?