`20.` We know a lot of people who live in Ho Chi Minh city.

`-` Cấu trúc: N(person) + who + V + O 

`-` who thay thế cho danh từ chỉ ngừoi (a lot of people) 

`21.` That house has just been sold. 

`-` Cấu trúc bị động thì HTHT: S + have/has + been + VpII + (by + O) 

`-` DHNB: just

`22.` Barry said that he couldn't go on working then. 

`-` Cấu trúc: S + said/told/said to + (O) + that + S + V + O 

`-` can => could (lùi thì)

`-` now => then 

`-` Cấu trúc: go on + V-ing

`23.` Although his salary was good, Jack gave up his job. 

`-` his good salary ( TTSH + adj + N) = his salary was good (TTST + N + tobe+ adj) - Chia was vì vế sau V (gave) chia ở thì QKD

`-` Cấu trúc: Although + S + V, S + V (cả hai vế cùng thì) 

`24.` My cousin used to visit me when he lived in Ha Noi. 

`-` Cấu trúc: S + used to + V-inf + O

`-` used to: đã từng

`25.` My grandfather, who used to be an astronaut, has been retired for ten years now. 

`-` Cấu trúc: N(person) + who + V + O

`-` who thay thế cho dành từ chỉ người (my grandfather)