1. For centuries, they … the ao dai in poems ( mention / haved mentioned/ mentioned). 2. The material … to make jeans ( use/ is used/ used). 3. The material … to make jeans is very strong ( use/ is used/ used). 4. Jeans are usually … by young people ( wear / wore / won ). 5. This work doesn’t need … ( do / to do / doing ). 6. He often makes his sister … ( cry / to cry / crying ). 7. How long … you … English? - For 3 year ( do - study / have - studied ).