Nhận biết Một con lắc lò xo gồm vật nặng khối lượng m = 0,4kg và lò xo nhẹ độ cứng k = 100N/m. Kéo vật khỏi vị trí cân bằng 2cm và truyền vận tốc có độ lớn 15 cm/s. Lấy π2 = 10. Tính năng lượng dao động của con lắc? A. 245J B. 2,45J C. 0,245J D. 24,5J

Một con lắc lò xo gồm một vật nặng khối lượng 0,4kg gắn vào đầu lò xo có độ cứng 40N/m. Người ta kéo quả nặng ra khỏi vị trí cân bằng một đoạn 4cm rồi thả nhẹ cho nó dao động. cơ năng dao động của con lắc là: A. 320J B. 6,4.10^-2J C. 3,2.10^-2J D. 3,2J

1/ Dùng khí CO để khử 8 g CuO người ta thu được sản phẩm khí.Dẫn toàn bộ sản phẩm khí vào 198,24 ml dd KOH 10%(D = 1,17g/ml).Hãy tính thể tích khí CO đã dùng(đkc) và khối lượng muối sinh ra. 2/ Lấy tòan bộ khí khi cho 45 gam CaCO3 hòa tan hòan tòan trong 200 ml dd HCl vào 500 ml dung dịch NaOH 0,4 M . Xác định muối thu được sau phản ứng.

1. My brother ( usually, go ) ……………………to church on Sundays

2. Mr. Brown (have ) ……………………….. two houses at the moment

3. I was sleeping when I ( hear ) ………………………. an explosion

4. I ( see )…………..John in the cinema yesterday .He (talk ) …………. to an old man at that time 5. Tom ( meet ) ……………………… Mary in 1986

6. When my father ( be )……. young , he sometimes (drive)…………….. to this village

7. He ( write ) …………………….a letter when he (break ) ………………………the pencil.

8. When I ( find )…………my purse , someone ( take )………… the money out of it .

9. When I (get )……….. to the station , the train ( leave )……………

10. The police ( pay )…………… no attention to Mary’s complain because she ( phone ) …………………….. them so many times before.

I. Phonetics A. Choose the word which has the underlined part pronounced differently from the rest 1. A. game​B. bridge​C. against ​D. garage 2. A. machinery ​B. march​C. cheerful​D. merchant 3. A. page​B. message ​C. danger​D. ringer B. Choose the word which is stressed differently from the rest 4. A. sympathy​B. loyalty​C. acquaintance​D. quality 5. A. rumor​B. believe​C. common​D. mutual II. Vocabulary and Grammar Choose from the four options given (marked A, B, C, and D) one best answer 6. He was so ________ that he distrusted all his friends. ​A. suspect​B. suspicious​C. suspicion​D. suspiciously 7. Friendship offers us great ________ in life. ​A. pleasure ​B. pleasant​C. please​D. pleased 8. Man is engaged in a ________ struggle with nature. ​A. constantly​B. constancy​C. inconstantly​D. constant 9. __________ is a two-sided affair. ​A. Friendly​B. Friendship​C. Friendliness​D. Friend 10. He is always __________ in words and deed. ​A. loyalty​B. loyally​C. loyal​D. loyalist 11. Daisy made me _________ him next week. ​A. promise calling​B. to promise calling​C. to promise to call​​D. promise to call 12. Some companies never allow ________ in their offices ​A. to smoke ​B. smoke​C. smoking ​D. smoked 13. They would __________ go by plane than spend a week traveling by train. ​A. love ​B. like​C. prefer​D. rather 14. I can hear a cat __________ at the window. ​A. scratches​B. scratching ​C. to scratch ​D. was scratching 15. If we leave now for our trip, we can stop __________ lunch at 11:00 sharp. ​A. to have​B. having​C. to have had​D. being having 16. He is very stubborn, so it will be difficult to __________ him to go. ​A. make​B. suggest ​C. let​D. persuade 17. She is busy ___________ for her wedding. ​A. shopping​B. shop​C. to shop​D. shopped 18. __________ Mr. Green nor his wife can drive. ​A. Not​B. Either​C. Neither​D. Both 19. I couldn’t repair my bicycle, __________ I didn’t have the right tools. ​A. although​B. because​C. because of​D. therefore 20. Two of the factories in our small town have closed. ___________, unemployment is high. ​A. Consequently​B. Because​C. So that​D. However

I. Phonetics A. Choose the word which has the underlined part pronounced differently from the rest 1. A. game​B. bridge​C. against ​D. garage 2. A. machinery ​B. march​C. cheerful​D. merchant 3. A. page​B. message ​C. danger​D. ringer B. Choose the word which is stressed differently from the rest 4. A. sympathy​B. loyalty​C. acquaintance​D. quality 5. A. rumor​B. believe​C. common​D. mutual II. Vocabulary and Grammar Choose from the four options given (marked A, B, C, and D) one best answer 6. He was so ________ that he distrusted all his friends. ​A. suspect​B. suspicious​C. suspicion​D. suspiciously 7. Friendship offers us great ________ in life. ​A. pleasure ​B. pleasant​C. please​D. pleased 8. Man is engaged in a ________ struggle with nature. ​A. constantly​B. constancy​C. inconstantly​D. constant 9. __________ is a two-sided affair. ​A. Friendly​B. Friendship​C. Friendliness​D. Friend 10. He is always __________ in words and deed. ​A. loyalty​B. loyally​C. loyal​D. loyalist 11. Daisy made me _________ him next week. ​A. promise calling​B. to promise calling​C. to promise to call​​D. promise to call 12. Some companies never allow ________ in their offices ​A. to smoke ​B. smoke​C. smoking ​D. smoked 13. They would __________ go by plane than spend a week traveling by train. ​A. love ​B. like​C. prefer​D. rather 14. I can hear a cat __________ at the window. ​A. scratches​B. scratching ​C. to scratch ​D. was scratching 15. If we leave now for our trip, we can stop __________ lunch at 11:00 sharp. ​A. to have​B. having​C. to have had​D. being having 16. He is very stubborn, so it will be difficult to __________ him to go. ​A. make​B. suggest ​C. let​D. persuade 17. She is busy ___________ for her wedding. ​A. shopping​B. shop​C. to shop​D. shopped 18. __________ Mr. Green nor his wife can drive. ​A. Not​B. Either​C. Neither​D. Both 19. I couldn’t repair my bicycle, __________ I didn’t have the right tools. ​A. although​B. because​C. because of​D. therefore 20. Two of the factories in our small town have closed. ___________, unemployment is high. ​A. Consequently​B. Because​C. So that​D. However