How long have the children following? Put in since or forперевести

где тут ошибка в вопросе?
спасибо!

Open the brackets and put the verbs into the proper tense form.+ перевод.
Mr Smith felt very bad. One of his friends 1 ................. (advise) him to go to a doctor. Mr Smith 2 ................... (decide) to follow his advice. When the doctor 3 ................... (examine) him he 4 ................... (tell) him to go to a village and stay there for a month, to go to bed early, drink milk, eat a lot of vegetables and smoke only one cigar a day. "If you 5 ........................ (take) my advice," 6 .................. (say) the doctor, "you 7 .................... soon ................... (feel) well." Mr Smith 8 ....................... (look) a little surprised when he 9 ..................... (hear) the doctor's advice, but the doctor 10 ................... (not see) it. A month later Mr Smith 11 ................. (come) to the doctor again. "How 12 ..................... (be) you?" the doctor 13 ..................... (ask) him. "You 14 .......................... (look) better now. 15 ..................... my advice ................... (help) you?" "Thank you," 16 ................... (say) Mr Smith, "117 ..................... (do) all you had recommended me to do. I 18 ................. (go) to the country, I 19 ................... (eat) a lot of vegetables. But one cigar a day nearly killed me. You see it 20 ................ (be) impossible to begin smoking at my age."

How long have you done at school ?
How many years have you studied English ?
Have you done all of this week`s homework yet ?
How many hours have you spent studying this week ?
Which sports have you played in the past month ?
ОТВЕТИТЬ НА ВОПРОСЫ
СРОЧНОО!!!

your best friend? 3. How long have you lived in your town / city / village? 4. How long have you been learning English? 5. How long have you known your English teacher?

b) Hom long they have been waiting for Laura?
c)How long have been they waiting for Laura
d)How long have they waiting for Laura?
e)How long they been waiting for Laura?

were some really old people. Mr Small went up to one of them. "I see that you're a very old man." he said.
"Yes. I am. I'm 90." the old man replied.
"Could you give the children here some advice about a balanced diet and a healthy lifestyle?" Mr Small asked.
"Sure. Follow my example. Don't smoke, don't drink, don't eat too much sugar or fat and drink lots of water."
At that moment Dr Foam found another old man. who looked older than the first one. He was sitting in a wheelchair, but his eyes were merry and bright.
"How old are you, sir?" Dr Foam asked.
"I'm ninety-five." the man replied.
"Can you tell us why you have lived so long?" Doctor Foam asked.
"It's easy. I always do exercise, and I don't smoke or drink. I spend a lot of time in the open air and I'm a vegetarian." Just then Mrs Bulmer decided to join in the conversation. She saw a very, very old man in the corner of the room. He had no teeth or hair and he couldn't see or hear very well, so she had to come very close to him. The children followed her.
"May 1 ask you a couple of questions, sir," she shouted.
"Yes." the old man whispered.
"Why have you lived so long, sir?" Mrs Bulmer asked.
"I don't know." the man replied.
"Tell us about your lifestyle," Mrs Bulmer continued.
"OK, then. I smoke thirty cigarettes a day and drink a bottle of whisky every day. Sometimes I also have two bottles of beer. I never eat vegetables or fruit and I live on chocolate and cakes."
"How old are you, sir?" Mr Bulmer exclaimed.
"I'm forty." the "old" man replied.