=> 2. My father has worked in this charity organization since last week. 4. They have worked in that factory for five years. 6. My brother has cleaned the lakes in the neighbourhood since last year. 9. He has donated books to help poor children for 5 years.
2. My father has worked in this charity organization since last week. QKĐ → HTHT: "started to work" (bắt đầu làm việc) → "has worked" (đã làm việc được...) "last week" là 1 mốc thời gian → dùng "since". 4. They have worked in that factory since 5 years ago. Như câu 2. 6. My bro has leaned the lakes in the neighborhood since last year. Như trên.
