EX8. Fill in the blank with "for" or "since". (Thì hiện tại hoàn thành) 1. My sister has been a student ………………. two years. 2. We've lived here ……………. 1990. 3. I haven’t seen Linh …………………. my birthday party. 4. She has been away ……………………. a year. 5. We've already waited ……………. five days. 6. They haven’t had any rain ………………… very long time. 7. That building has been there …………………….. the 19th century. 8. I have known them …………….. many years. 9. They have only been there …………….. a few minutes. 10. My brother works for a company called FPT. He has worked for them ............ he