Có 3 oxit màu trắng: MgO, Al2O3, Na2O. Có thể nhận biết được các chất đó bằng thuốc thử sau (1 Điểm) Chỉ dùng quì tím Chỉ dùng axit Chỉ dùng phenolphtalein Dùng nước

Một người kéo đều một vật từ giếng sâu 8 m trong 30 giây. Người ấy phải dùng một lực F = 180 N. Công và công suất của người kéo là bao nhiêu?

quãng đường AB dài 90km.Một ô tô đi từ A đến B vs vận tốc và thời gian dự định. Sau khi đi đc 1/3 quãng đường AB thì ôtô nghỉ lại 20p .Vì vậy quãng đường còn lại để đến B đúng dự định ôtô phải tăng vận tốc thêm 6km/h. Tính vận tốc dự định của ôtô.

tìm 2% của 1000 tìm 5% của 1000 tìm 25% của 1000

Mọi người giúp mình bài 1 tiết 70 với,mình đang cần gấp

Một con ngựa kéo một cái xe đi đều với vận tốc 9km/h. Lực kéo của con ngựa là 200N. a. Tính công suất của con ngựa. b. Chứng minh rằng P= F.v

Fill in the blanks with suitable words to complete the passage. windsurfing beach island happy hotel friends fruit vacation car food Dear Karen, Hi, there! My (1) ………………. was great! I visited my (2) …………… in Puerto Rico. I stayed at a nice (3) …………… near a beautiful (4) ……………… We rented a (5) …………… and traveled around the (6) ……………… I tried to learn (7) ……………………, but it was difficult. I enjoyed the (8) ………………. And really loved the fresh (9) ……………… I talked to a lot of local people there. I’m really (10) …………… See you soon! Loves, Ken VIII. Fill in the blanks with suitable prepositions to complete the sentences: Ex: I get up at 6 o’clock every morning. 1. Do you go to school ……… foot or ……… bike? 2. My house is ……… Le Loi Street, her house is ……… 19 Le Lai Street. 3. We are living ……… our parents ……… Ho Chi Minh City. 4. She is interested ……… Literature and English. 5. My birthday is ……… 29 th February, my mother’s birthday is ……… August. 6. Vegetables are very good ……… your health. 7. I received the letter ……… your aunt last week. 8. He wrote a letter ……… his mother last week. 9. These books cost ……… $100. 10. They are playing video games ……… the moment. IX. Rewrite the sentences without changing the first meaning: 1. Let’s go to the movie theater.  What about ………………………………………………………………………..? 2. The film is very interesting.  What ……………………………………………………………………………….! 3. Sam’s hair is longer than my hair.  My hair ……………………………………………………………………………. 4. The meal was really delicious.  What ……………………………………………………………………………….! 5. Why don’t we go camping this Sunday?  Would ……………………………………………………………………………..? 6. His house is cheaper than our apartment.  Our apartment ………………………………………………………………………

IV. Give the correct form of verbs given. 1. They (join) ………………. the English competition last week. 2. Lan’s sister usually (get) ……………… up at 6 o’clock in the morning. 3. What time …………… your mother (cook) ……………… for dinner yesterday? 4. What ……… they (do) …………… now? – They (clean) …………………… their car. 5. Mai (not go) ……………………. to the supermarket next morning. 6. It (rain) ………………… heavily now. You should (stay) ………… at home and (read) ………… books. 7. She (be) ……………… fourteen on her next birthday. 8. I (mail) ………………… this letter tomorrow. 9. He (phone) ……………… his parents three or four times a week. 10. Hoa (not visit) …………………… the museum with her class last Sunday. 11. …………… (be) you at Paul’s party last night? 12. Listen! The birds (sing) ………………… 13. Could you (show) ……………… me the way to the bank? 14. He (be) …………… never late for school. 15. We (buy) ……………… her a lot of gift for her last birthday. V. Supply the correct form of the words given. 1. Driving too fast is very ……………………. DANGER 2. The ……………… fish in the aquarium are the most beautiful. COLOR 3. Please listen ……………… to the teacher. CAREFUL 4. Quang Hai is a …………… football player. SKILL 5. Minh is not ……………… SPORT 6. There is a restaurant, a clinic and a hospital in my …………………… NEIGHBOR VI. Make questions for the underlined words. 1. Nam is doing his homework. ..........................................................................................................................? 2. My father traveled to Tokyo by plane. ..........................................................................................................................? 3. Hoa and Mai will come here tomorrow evening. ..........................................................................................................................? 4. My mother was in Da Nang last week. ..........................................................................................................................? 5. Lan left home at 6.30 yesterday morning. ..........................................................................................................................? 6. Hoa bought a cap and a poster at the souvenir shop. ..........................................................................................................................? 7. Mr. Pike teaches me English this year. ..........................................................................................................................? 8. My new skirt is black. ..........................................................................................................................? 9. Mai will stay in Hue for five days. ..........................................................................................................................? 10. Nam went to Hanoi with his family on summer vacation. ..........................................................................................................................?

(-15)+23+(-25)+(-23) Giúp mình vs ạ

Mn ơi giúp mk 2 bài này vs cảm ơn các bn nhiều nhiều