、用 since 和 for 填空 1.______two years 2.____two years ago 3.___last month 4.______ 1999 5._______yesterday 6._______ 4 o’clock 7 4 hours 8._____an hour ago 9. ___we were children 10._____ lunch time 11.____ she left here 12. He has lived in Nanjing ___ the year before last. 13. I’ve known him ______ we were children. 14. Our teacher has studied Japanese ______ three years. 15. She has been away from the city ______ about ten years. 16. It’s about ten years __________ she left the city.