1. There (not/ be).................. many high- rise buildings in Ha Noi before 1990
2. Goalkeeper Bui Tien Dung (have).................. different manual labour jobs before he became a professional football player
3. Few people (ride)................ motorbikes in HCM city before 1983
4. I got a high mark in English because I (study) ................... hard before the exam
5. How long (you/learn)...................English before you travelled to the U.S?
Mọi người giúp e vs
1. hadn't been
2. had had
3. had ridden
4. had studied
5. had you learned