khoahoc.vietjack.com

Danh sách câu hỏi ( Có 2,481,718 câu hỏi trên 49,635 trang )

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions. High maths abilities, bad school lives     Teachers first noticed Cameron Thompson's talent for numbers when he was four years old and at pre- school. Throughout primary school, Cameron Thompson's best subject was maths. Then, when he was eleven, he took a maths test prior to entering secondary school. The test was out of 140; Cameron scored 141. 'I broke the system,' he recalls.      Since then, he has continued to progress quickly. He passed two GCSEs (maths and further maths) at the age of eleven, and then got the highest grade in his maths A-level before the end of that same academic year.  He is now fourteen years old and studying for a degree in maths; a remarkable achievement bearing in mind his age.      But his academic achievements have not always been matched by social success. ‘I have the social ability of a talking potato,’ he admits. In other words, he feels more at ease with numbers than among other teenagers. 'Most people my age do despise me. I've been like this for years.'      Communication is not one of Cameron's strong points and, aside from the problems this causes socially, it is now beginning to affect his marks in mathematics. This is because at undergraduate level, he is expected to give reasons for his answers alongside the answers themselves. Cameron's difficulty is that he often doesn't know how he has arrived at the answers, even though the answers are usually correct. Cameron and his family have recently moved house and Cameron is due to start at a new school. He regards it as a chance to make a fresh start and make some friends. But his mother, Alison, has a few worries concerning his lack of social skills. While she describes Cameron as 'very sensitive', she also acknowledges that he is socially naive and often oblivious to signals from other people.      The new school specialises in dealing with students who, like Cameron, excel academically but find it difficult to relate to other students. And indeed, on his first day, Cameron did make a new friend – a boy called Tim - mainly owing to a shared dislike of Justin Bieber's music.      Recently, a maths professor from Cambridge University has been looking at Cameron's work. His advice to Cameron is perhaps surprising. Professor Imre Leader thinks Cameron should slow down, stop taking maths exams, and wait until he is eighteen before doing a degree. "There's quite an important distinction” he explains, “between taking lots of exams as fast as you can, and relaxing and enjoying the level that you are at- what we call enrichment”, Professor Leader believes Cameron will do better in the long run if he stops trying to progress so quickly. And although Cameron does not want to finish his current degree, he isn't making any academic plans beyond that. He goes to a weekly karate class after school. And recently, he went to a computer games convention with some friends from karate.           Since turning fourteen, Cameron's feelings towards girls have changed. As he puts it, “I started to like them instead of being disgusted by them.' He's even been on a first date - without his parents. And in general, he feels less isolated and unusual than he did before. 'There are other people like me - high maths abilities, bad school lives - I am not alone - Spooky.'Cameron's problems with communication _______ 

Xem chi tiết 678 lượt xem 4 năm trước

Cho biết một đoạn mạch gốc của gen A có 15 nuclêôtit là: 3'AXG GXA AXA TAA GGG5'. Các côđon mã hóa axit amin: 5'UGX3', 5'UGU3' quy định Cys; 5'XGU3', 5'XGX3'; 5'XGA3'; 5'XGG3' quy định Arg; 5'GGG3', 5'GGA3', 5'GGX3', 5'GGU3' quy định Gly; 5'AUU3', 5'AUX3', 5'AUA3' quy định Ile; 5'XXX3', 5'XXU3', 5'XXA3', 5'XXG3' quy định Pro; 5'UXX3' quy định Ser. Đoạn mạch gốc của gen nói trên mạng thông tin quy định trình tự của 5 axit amin. Theo lí thuyết, có bao nhiêu phát biểu sau đây đúng?I. Khi đoạn gen A tiến hành tổng hợp chuỗi pôlipeptit các lượt tARN đến tham gia dịch mã có các anticôđon theo trình tự 3'AXG5', 3'GXA5', 3'AXG5', 3'UAA5', 3'GGG5'.II. Nếu gen A bị đột biến thêm cặp G-X ngay trước cặp A-T ở vị trí thứ 12 đoạn mARN được tổng hợp từ đoạn gen nói trên chỉ thay đổi thành phần nuclêôtit tại côđon thứ 5.III. Gen A có thể mã hóa được đoạn pôlipeptit có trình tự các axit amin là Cys – Arg -Cys– Ile – Pro.IV. Nếu gen A bị đột biến thay thế cặp A-T ở vị trí thứ 9 của đoạn ADN nói trên bằng cặp T – A thì quá trình dịch mã không có phức hợp axit amin-tARN tương ứng cho côđon này.

Xem chi tiết 1.2 K lượt xem 4 năm trước

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions. High maths abilities, bad school lives     Teachers first noticed Cameron Thompson's talent for numbers when he was four years old and at pre- school. Throughout primary school, Cameron Thompson's best subject was maths. Then, when he was eleven, he took a maths test prior to entering secondary school. The test was out of 140; Cameron scored 141. 'I broke the system,' he recalls.      Since then, he has continued to progress quickly. He passed two GCSEs (maths and further maths) at the age of eleven, and then got the highest grade in his maths A-level before the end of that same academic year.  He is now fourteen years old and studying for a degree in maths; a remarkable achievement bearing in mind his age.      But his academic achievements have not always been matched by social success. ‘I have the social ability of a talking potato,’ he admits. In other words, he feels more at ease with numbers than among other teenagers. 'Most people my age do despise me. I've been like this for years.'      Communication is not one of Cameron's strong points and, aside from the problems this causes socially, it is now beginning to affect his marks in mathematics. This is because at undergraduate level, he is expected to give reasons for his answers alongside the answers themselves. Cameron's difficulty is that he often doesn't know how he has arrived at the answers, even though the answers are usually correct. Cameron and his family have recently moved house and Cameron is due to start at a new school. He regards it as a chance to make a fresh start and make some friends. But his mother, Alison, has a few worries concerning his lack of social skills. While she describes Cameron as 'very sensitive', she also acknowledges that he is socially naive and often oblivious to signals from other people.      The new school specialises in dealing with students who, like Cameron, excel academically but find it difficult to relate to other students. And indeed, on his first day, Cameron did make a new friend – a boy called Tim - mainly owing to a shared dislike of Justin Bieber's music.      Recently, a maths professor from Cambridge University has been looking at Cameron's work. His advice to Cameron is perhaps surprising. Professor Imre Leader thinks Cameron should slow down, stop taking maths exams, and wait until he is eighteen before doing a degree. "There's quite an important distinction” he explains, “between taking lots of exams as fast as you can, and relaxing and enjoying the level that you are at- what we call enrichment”, Professor Leader believes Cameron will do better in the long run if he stops trying to progress so quickly. And although Cameron does not want to finish his current degree, he isn't making any academic plans beyond that. He goes to a weekly karate class after school. And recently, he went to a computer games convention with some friends from karate.           Since turning fourteen, Cameron's feelings towards girls have changed. As he puts it, “I started to like them instead of being disgusted by them.' He's even been on a first date - without his parents. And in general, he feels less isolated and unusual than he did before. 'There are other people like me - high maths abilities, bad school lives - I am not alone - Spooky.' Cameron met a boy at his new school who _______ 

Xem chi tiết 352 lượt xem 4 năm trước

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions. High maths abilities, bad school lives     Teachers first noticed Cameron Thompson's talent for numbers when he was four years old and at pre- school. Throughout primary school, Cameron Thompson's best subject was maths. Then, when he was eleven, he took a maths test prior to entering secondary school. The test was out of 140; Cameron scored 141. 'I broke the system,' he recalls.      Since then, he has continued to progress quickly. He passed two GCSEs (maths and further maths) at the age of eleven, and then got the highest grade in his maths A-level before the end of that same academic year.  He is now fourteen years old and studying for a degree in maths; a remarkable achievement bearing in mind his age.      But his academic achievements have not always been matched by social success. ‘I have the social ability of a talking potato,’ he admits. In other words, he feels more at ease with numbers than among other teenagers. 'Most people my age do despise me. I've been like this for years.'      Communication is not one of Cameron's strong points and, aside from the problems this causes socially, it is now beginning to affect his marks in mathematics. This is because at undergraduate level, he is expected to give reasons for his answers alongside the answers themselves. Cameron's difficulty is that he often doesn't know how he has arrived at the answers, even though the answers are usually correct. Cameron and his family have recently moved house and Cameron is due to start at a new school. He regards it as a chance to make a fresh start and make some friends. But his mother, Alison, has a few worries concerning his lack of social skills. While she describes Cameron as 'very sensitive', she also acknowledges that he is socially naive and often oblivious to signals from other people.      The new school specialises in dealing with students who, like Cameron, excel academically but find it difficult to relate to other students. And indeed, on his first day, Cameron did make a new friend – a boy called Tim - mainly owing to a shared dislike of Justin Bieber's music.      Recently, a maths professor from Cambridge University has been looking at Cameron's work. His advice to Cameron is perhaps surprising. Professor Imre Leader thinks Cameron should slow down, stop taking maths exams, and wait until he is eighteen before doing a degree. "There's quite an important distinction” he explains, “between taking lots of exams as fast as you can, and relaxing and enjoying the level that you are at- what we call enrichment”, Professor Leader believes Cameron will do better in the long run if he stops trying to progress so quickly. And although Cameron does not want to finish his current degree, he isn't making any academic plans beyond that. He goes to a weekly karate class after school. And recently, he went to a computer games convention with some friends from karate.           Since turning fourteen, Cameron's feelings towards girls have changed. As he puts it, “I started to like them instead of being disgusted by them.' He's even been on a first date - without his parents. And in general, he feels less isolated and unusual than he did before. 'There are other people like me - high maths abilities, bad school lives - I am not alone - Spooky.Professor Leader thinks Cameron should _______ 

Xem chi tiết 463 lượt xem 4 năm trước