1. The last time I met my uncle was 5 years ago.

=> for 5 years -> 5 years ago

     haven't met -> the last time I met

2. The cello is slower than the violin. 

=> is not as slow >< is slower than

3.My mom isn't as patient as my dad.

(Câu này đúng rồi)

4. I have already read that book three times.

=> the third time -> three times

5. These flowers are watered every morning.

=> water -> are watered (câu bị động)

`1.` The last time I met my uncle was 5 years ago

The last time + S + V_ed/ V2 + was + mốc thời gian/ khoảng thời gian

`2.` The cello is slower than the violin 

$S_{1}$ + be + (not) + adj-er/ more adj + than + $S_{2}$

`3.` My mom isn't as patient as my dad

$S_{1}$ + be + (not) + as + adj + as + $S_{2}$

`4.` I have read that book before

S + has/ have + V_ed/ V3 + before

`5.` These flowers are watered by my father every morning

S + is/ am/ are + V_ed/ V3 + (by O)