Hoàn thành các câu với hình thức hoàn hảo hiện tại (tích cực hoặc tiêu cực) của các động từ trong ngoặc. 1. I __________________ (have) four exams so far this month. 2. Mr Tan __________________ (teach) in this school for over ten years. 3. You __________________ (not stop) talking since you got here! 4. Scientists __________________ (find) more than 30 unknown insects. 5. She __________________ (not see) Nathan since he left the town. 6. Someone __________________ (break) a window in our classroom. 7. We __________________ (not decide) what to get Mark for his birthday yet. 8. I __________________ (already/ finish) my homework. It was easy! 9. Jorge __________________ (not play) tennis since his injury. 10. My parents __________________ (be) to Australia three times