`1` She wanted to know what they were doing .

`-` Gián tiếp ''Wh-question'' .

`@` S + asked + O + Wh-question + S + V(lùi thì) + O .

`-` are `->` were .

`2` When I was thinking line about the weekend plan , Jack arrived .

`-` Hành động đang xảy ra thì có hành động khác xen vào .

`->` When/while + S + was/were + V-ing/N + O , S + V(quá khứ) + O .

`3` When I was watching TV at `8` o'clock yesterday , the doorbell rang .

`-` Hành động đang xảy ra thì có hành động khác xen vào .

`->` When/while + S + was/were + V-ing/N + O , S + V(quá khứ) + O .

`4` A robot cleaned the floor more quickly than all the students in my class .

`-` So sánh hơn trạng từ dài .

`@` S1 + V + more + adv-dài + than + S2 .

`5` The new computer system works more effectively than the old one .

`-` So sánh hơn trạng từ dài .

`@` S1 + V + more + adv-dài + than + S2 .