giúp em với ạ em cần gấp ak

1. Why they dig canals? 
- Hỏi lí do: Why
- Câu nghi vấn QKĐ: Wh/H + did + S + V + O?
2. It's Vietnamese tradition to reunite with family at Tet.
- HTĐ: S + be (is/am/are) + O
- adj + N
- reunite with family: đoàn tụ với gia đình
1. I am keen on collecting birthday cards.
- find sth interesting = be keen on doing sth
2. She prefers socializing with friends to watching TV. 
- prefer doing sth to doing sth: thích làm gì hơn làm gì
3. Living in the city is more convenient than living in the city.  
- So sánh hơn với tính từ dài: S + be + more + adj + than + O
5. She has to revise for the test tomorrow; therefore, she won't see the film on TV tonight.
- S1 + V1 + because + S2 + V2 = S2 + V2; therefore, S1 + V1