Giúp mình bài 2.3 với mn ơii. Please mình cần gấp lắm ạ.

Giúp em với ạ (tiện thể cho em biết công thức tính % của hạt ạ) Nguyên tử B có tổng số hạt là 21. Số hạt không mang điện chiếm 33,33%. Xác định cấu tạo của nguyên tử B. Số hạt không mang điện chiếm 33,33%. Xác định cấu rại của nguyên tử B

a) {-3x + 2. [45 - x - 3 (3x + 7) - 2x ]+4x } = 55 b) 103 - 57 : [-2. (2x - 1$)^{2}$ - (-9$)^{0}$] = -106

Giải hệ phương trình: $\left \{ {{2(x+y)+3(x-y)=4} \atop {(x+y)+2(x-y)=5}} \right.$

chuyển các câu sau sang câu phủ định: 1.He is as tall as I am/me 2.she is as beautiful as her morther is/her mother 3.his close friend is as intelligent as her is/her morther 4.he runs as fast as I run/I do/me 5.she cooks as well as her mother cooks/ her mother does/her mother. 6.he studies english as well as his plays soccer/playing soccer/soccer.

1. Scientists say that exhaust fumes are............. our city. A. poisoning B. poisonous C. poison) 2. Many seabirds were ..........................because of the oil spill. (die/ death/ dead ) 3. Waste from households will gradually ............................. the lake (contaminate/ contamination/ contaminated) 4. Trees can’t grow here because the soil is too ......................... (pollute/ polluted/ pollution) 5. That fierce storm left behind badly......................... buildings. (damage/ damaged/ damaging) 6. What’s a ......................? It’s a substance that contaminates something. (pollute/ polluted/ pollutant) 7. Don’t drink that water. It’s __________. A.damaged B.dumped C.contaminated 8. The team’s success was largely __________ to her efforts. A.because B.due C.since 9. By the time we got to the cinema, the film __________. A.started B.had started C.starting 10. All our English teachers are __________ speakers. A.native B.original C.foreign 11. If you __________ the president, what would you do to help the environment? A.are B .had been C .were 12. Eating too much sugar can __________ to health problems. A.cause B.lead C.make 13. The heavy rain has caused __________ in many parts of the country. A.storms B.floods C.drought 14. The Maori in New Zealand greet each other by _____ their noses. A.punching B.touching C.blowing 15. If the factory ___ dumping poison into the lake, all the fish and other aquatic animals will die. A. continues B. continued C. will continue 16. _______ has made the fish die. A. Waterpollution B. thermal pollution C.noise pollution 17. If the air wasn’tdirty, I ________ so much. A. wouldn’t sneeze B. sneeze C. would sneeze 18 .If you _____ the president, what would you do to help the environment ?A.are B. will be C.were 19. Air___, together with littering, is causing many problems in our cities today. A. pollute B. pollution C. polluting 20. If we __water carefully, more people will have fresh water. A. use B. would use C. using 21. A severe tropical____ is called a typhoon. A. drought B. rain C. storm 22. Noise pollution can lead to________loss. A. looking B. hearing C. listening 23. If I________a millionaire now, I________travel around the world. But in fact, I am very poor and have no money. A. were/ would B. am/ will C. were/ will 24. Emergency teams are still clearing up the ____ from the plane crash. A.debris B.dust C.piece 25............is a sudden, violent shaking og the earth’s surface A. drought B. flood C. earthquake 26. ........ is a long period when there is no rain and not enough water for people, animals and plants A. A. drought B. flood C. earthquake 27. Many people died in the accident. - .................... A. That’s great B. That’s a relief! C. Oh no!

Task 2: Put the given phrases into the right column.(2ms) - an American professional golfer, - Sportsman of The Year, - a famous American tennis player, - among the top ten players throughout the world, - Female Athlete of the Year, - broke the record, - the tournament's youngest winner, - learnt to play tennis at the age of three, TIGER WOODS SERENA WILLIAMS Task 3: Decide if the following statements are True or False.(1m) Statements True (T) False (F) 1.Tiger Woods was born on December 30, 1975 in Michigan. 2.Tiger Woods reached the number one position in the World Golf Rankings in June 1997. 3.Serena Williams was the tournament's youngest-ever winner in April 1997 4.Serena Williams played golf and tennis professionally. 5.Serena Williams achieved the number one ranking in the world in 2002

Giúp mình với ạ Vote 5 sao nha

Câu 1:Dựa vào hình 51.1 và thông tin trong sgk trang 153- 154 hãy hoàn thiện bảng sau: Nội dung Đặc điểm Vị trí địa lí, phạm vi lãnh thổ Diện tích trên 10 triệu km2, nằm trong khoảng giữa 2 vĩ tuyến 36OB và71OB……………………………….................................... Tiếp giáp châu……………………………………….., giáp các biển…………………………………………..và đại………….. dương………………………….. Bờ biển dài………………………………………………………. Các bán đảo……………………………………………………… Địa hình Đồng bằng …………………………………………………………………… …………………………………………………………………… Núi già ……………………………………………………………………. …………………………………………………………………… Núi trẻ ………………………………………………………………………. ……………………………………………………………………… Câu 2: Dựa và hình 51.1 và 51.2 và thông tintrong sgk trang 153- 157 hãy giải thích vì sao khu vực phía tây của Châu Âu có khí hậu ấm áp mưa nhiều hơn khu vực phía đông

1.Their teacher / will / sad / if / they / not pass / exam. 2. If / you / not / say / sorry / they / will / not / forgive / you. 3.If / you / want / healthy / you / should / not / continue / smoke. 4. The plants / may / not / need / fertilizer / if / soil / rich. 5. You / can / not / buy / this watch / if / you / not / have / enough / money. thanks