Answer: B) Helen has collected stamps since she was 7.
Explanation for this question is being written.
Answer: A) Since
Answer: D) She hasn't come back to her hometown for 4 years.
Answer: C) Since
Answer: B) Left
Answer: B) Started
Answer: A) For
Answer: B) Since
Answer: C) I have lived in Canada for 10 months.
Answer: C) I have lived here ever since I moved to the city.
Answer: A) Since we were young.
Answer: D) Since
Answer: A) A
Answer: B) For many months.
Answer: C) Since when have they lived here?
Answer: B) I am studying since 2020.
Answer: B) Was
Answer: C) He has left / have heard.
Answer: A) 'For' indicates duration; 'since' indicates a starting point.
Answer: B) I haven't eaten sushi since the last summer.
Answer: B) Present perfect.
Answer: B) Since November.
Answer: D) I last saw.
Answer: A) I haven't seen her for a week.
Answer: D) Perfect Progressive.
Answer: A) David has been in love with Patricia since they were teenagers.
Answer: C) How long is it since you spent Christmas with your family?
Answer: B) PRESENT PERFECT.
Answer: C) Has / since.
Answer: C) I haven't seen him since 1998.
Answer: D) It has been two years since we last went to a cinema.