Bài 1 cần mình câu a,d thui nha,nhanh nhé ạ,mơn

3/(x^4-x^3+x-1) + 1/(x+1-x^4-x^3) -4/(x^5 -x^4+x^3-x^2 +x-1)

Cho góc aOb=35 độ, aOa' bOb' lần lượt kề với aOb, có số đo là 90 độ. Vẽ Ox, Oy lần lượt là tia phân giác của aOa' bOb'. a) CMR: Ox và Oy không phải là 2 tia đối nhau B) Để Ox và Oy là hai tia đối nhau aOb = ? độ mình cần gấp cảm ơn

một con chim đang bay trên không trung với tốc độ 10m/s, tính vận tốc để sau 5' con chim có mặt trên mặt đất, biết khoảng cách từ đất đến chỗ con chim theo đường chim bay là 8m

vẽ sơ đồ lắp đặt mạch điện gồm: 1 cầu chì, 1 ổ điện, 1 công tắc điều khiển 1 bóng đèn

Reading: Bach Ma National Park is located in central Vietnam in the province of ThuaThien Hue, around 70 km south of the capital of Hanoi and 1000 km from Ho Chi Minh City. The national park covers an area of about 22,000 ha in the districts of PhuLoc and Nam Dong. With Steep Mountain and dense forests, this area is the home to a wide variety of animals and plants. At the base of the mountains, there is a tropical monsoon forest, above 900 m sub-tropical forest. There are species from both northern and southern Vietnam. Bach Ma is recognized as one of the area of Indochina with high biodiversity. Bach Ma mountain peak is the highest point in the park at 1450 m above the sea level and is only 18 km away from the coast. The following words appearing in the passage complete the sentences with a suitable one. sub-tropical variety covers highest 1. You are surprised at the _____________ of animals and plants in Bach Ma national park. 2. ___________________ relates to an area near a tropical area. 3. Water ___________________ seventy-five percent of the earth. 4. Phanxipang is the _________________ mountain in Vietnam. Answering the following questions: 5. Where is Bach Ma national park? _____________________________________________________. 6. How far is it from Ho Chi Minh City to Bach Ma national park? _____________________________________________________.

Cho tam giác ABC ,trên BC lấy điểm M sao cho BM =2MC. Trên AC lấy điểm N sao cho AN =NC . Tính diện tích tam giác ABC, biết diện tích tam giác MNC là 3cm2 .

Cho ΔABC (A =90 độ), vẽ tia phân giác của B cắt AC tại D, kẻ DN⊥BC tại N a) Chứng minh: ΔDBA = ΔDBN b) Chứng minh: ΔBNA cân ( Nhớ vẽ hình)

đặc điểm hệ hô hấp của lưỡng cư, bò sát đặc điểm hệ tuần hoàn của lớp lưỡng cư. giúp mình nha

I. Pronunciation: Choose the word whose stress is put differently from the other in group: 1. A. animal B. conservation C. plenty D. various 2. A. submarine B. create C. destruction D. sub-tropical Choose the word whose underlined part is pronounced differently from the other: 3. A. played B. closed C. studied D. laughed ( gạch chân ed) 4. A. pat B. man C. cat D. plant (gạch chân a) II. Vocabulary & Grammar: Choose the best answers to complete the following sentences: 5. Bach Thao zoo ___ many kinds of wild animals, such as lion, tiger. A. covers B. contains C. includes D. consists 6. She ____ to take part in the excursion. A. don’t invite B. haven’t invited C. was not invited D. have been invited 7. QuangOai School was ___ in 1961. A. began B. prepared C. appeared D. established 8. If it ___ fine tomorrow, we’ll go to visit Ba Vi national park. A. is B. was C. would be D. should be 9. What ___ happen if there were no plants on the Earth? A. will B. shall C. would D. does 10. Three-quarters of the earth is covered by ___. A. seas and oceans B. mountains C. soil D. sand 11. We should do something to ___ endangered animals. A. protect B. harm C. purchase D. exchange 12. Vietnam lies in the ___ climate. A. arctic B. pacific C. tropical D. temperate 13. Water ___ held on land by vegetation. A. can be B. were C. are D. was 14. ___ is the most effective way to protect the environment. A. Conservation B. Conservatory C. Conservationist D. Conservatism 15. Today’s scientists send submarines to ___ the undersea world. A. investigating B. investigated C. investigate D. investigation 16. ___ means the existence of different kinds of animals. A. Environment B. Habitat C. Biodiversity D. Marine life 17. Huong pagoda is ___ 50 km from Hanoi. A. situated B. located C. A and B D. bordered 18. Every year, thousands of animals and plants are being ___. A. eliminated B. cut down C. prohibited D. bought 19. __________is a state of being polluted. A. Environment B. Contamination C. Conservation D. conversation 20. The wildlife of animals and plants ________seriously. A. is being threatened B. are being threatened C. is being threatening D. are threatening