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Gọi x là số tế bào mẹ ban đầu có bộ lưỡng bội =2n,k là số lần nguyên phân liên tiếp 1.tổng số tế bào con được tạo thành =2k.x 2,số tế bào mới được tạo thành từ nguyên liệu môi trường =(2k-1)x
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Viết cau mệnh lệnh dựa vào dong từ cho sẵn 1._________upstairs(to go) 2._____________in this lake(not/to swim) 3.___________your homework(to do) 4.__________football in the yard(not/to play) 5.___________your teeth(to brush) 6._____________during the lesson(not/to talk) 7._____________the animal in the zoo(not/to feed) 8.__________the Instructions(to read) 9.____________late for school(not/tobe) 10.____________your mobiles(to switch off) 11.___________our brother(to ask) 12._____________a pencil(not/to use) 13.__________up(to hurry) 14.___________quiet(to be) 15.__________the police(not/to call) 16.________your beds(to make) 17. Please__________the gap(to mind) 18._____________dad about my accident(not/to tell) 19. Please____________in this room(not/to smoke) 20.Let's_____________her mother in the kitchen(to help) giup tớ với cac ban

2 Mark the letter A, B, C, or D on your answer sheet to indicate the word(s) OPPOSITE in meaning to the underlined word(s) in each of the following questions. Question 16. Thousands are staving because of the failure of this year’s harvest. A:hungry B:full C:poor D:rich 3 Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits blank (17). Do you know about the history of Jeans? Jeans are very popular with (17)________people all over the world. Some people say that jeans are the “uniform” of youth. But they haven’t always been popular. The story of jeans (18)________almost two hundred years ago. People in Genoa, Italy made pants. The cloth made in Genoa was (19)________“jeanos”. The pants were called “jeans”. In 1850, a salesman in California began selling pants made of canvas. His name was Levi Strauss. Because they were so strong, “Levi’s pants” became (20)________with gold miners, farmers and cowboys. Six years later Levis began making his pants with blue cotton cloth called denim. Soon after, factory (21)________in the US and Europe began wearing jeans. A:rich B:poor C:young D:old 5 Mark the letter A, B, C or D on your answer sheet to indicate the most suitable response to complete each of the following exchanges. Question 13. Helen: “What a lovely house you have!” Mary: “__________________” A:Of course not. it’s not costly. B:No problem C:I think so. D:Thank you. Hope you will drop in. 6 Choose the word whose underlined part is pronounced differently from the others. A:visited B:celebrated C:persuaded D:looked 7 Choose the correct sentence (A, B, C or D) made from the suggested words. Question 22. Teacher’s Day/ celebrate/ twentieth/ November. A:Teacher’s Day was celebrated on the twentieth of November. B:Teacher’s Day celebrates on the twentieth of November C:Teacher’s Day is celebrated on the twentieth of November. D:Teacher’s Day celebrated on the twentieth of November 8 Choose the correct sentence (A, B, C or D) that has the same meaning to the given one. Question 24. “Why don’t you use a password to protect your files?”, An said to me. A:An encouraged me to using a password to protect my files. B:An advised me to used a password to protect my files. C:An asked me why I didn’t use a password to protect my files. D:An advised me to use a password to protect your files. 9 Choose the best answer A, B, C or D to complete the sentence. Question 9. What __________________ if you saw a UFO? A:did you do B:will you do C:would you do D:do you do 10 Mark the letter A, B, C or D on your answer sheet to indicate the word(s) CLOSEST in meaning to the underlined word(s) to each of the following questions. Question 15. As a government official, Benjamin Franklin often traveled abroad. A:widely B:secretly C:overseas D:alone 11 Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits blank (18). Do you know about the history of Jeans? Jeans are very popular with (17)________people all over the world. Some people say that jeans are the “uniform” of youth. But they haven’t always been popular. The story of jeans (18)________almost two hundred years ago. People in Genoa, Italy made pants. The cloth made in Genoa was (19)________“jeanos”. The pants were called “jeans”. In 1850, a salesman in California began selling pants made of canvas. His name was Levi Strauss. Because they were so strong, “Levi’s pants” became (20)________with gold miners, farmers and cowboys. Six years later Levis began making his pants with blue cotton cloth called denim. Soon after, factory (21)________in the US and Europe began wearing jeans. A:starts B:started C:start D:was starting 12 Choose the best answer A, B, C or D to complete the sentence. Question 12. He asked me what the conservationists __________ so far to protect our environment. A:had done B:have done C:do D:did 13 Choose the word whose underlined part is pronounced differently from the others. A:child B:school C:chopsticks D:church 14 Choose the correct sentence (A, B, C or D) that has the same meaning to the given one. Question 25. They have built a new school in our village recently. A:A new school has built in our village recently. B:A new school has to be built in our village recently. C:A new school was built in our village recently. D:A new school has been built in our village recently

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