Bài `6` :
`1.` was playing
`2.` Were you driving
`3.` was raining
`4.` were travelling
`5.` wasn't listening
`6.` was living
`7.` were they doing
`8.` wasn't studying
`9.` Was Caroline skiing
`10.` weren't sleeping
* Cấu trúc Past continuous form : thì quá khứ tiếp diễn
`-` Câu khẳng định : S + was/were + V-ing.
`-` Câu phủ định : S + was/were + not + V-ing
`-` Câu hỏi : Was / Were + S + V-ing?
`-` Dấu hiệu nhận biết : While (trong khi), When (Khi), at that time (vào thời điểm đó), “when” khi diễn tả một hành động đang xảy ra và một hành động khác xen vào,...