3. It has been over two years since she worked here. 
=> The last time
4. Ronaldo, a genious footballer now, scored over 60 goals for Real Madrid this football season.
=> Ronaldo, who
 11. Why don't we keep the school yard clean?
=> I suggest that the school yard
12. Although we don't study in the same class, we often help each other.
=> In spite
13. The poem is short, but many students can't leam it by heart.
=> Even though
14.I bought this air-conditioner because it consumes less electricity than the others. Chuong
=> This air-conditioner
15. Columbus, a great explorer, discovered America.
=> Columbus, who
16. I think you should follow your teacher's advice.
=> If I
17.I find it hard to pronounce Spanish words.
=> I wish
18. I will bring some water because I am afraid that there is no water supply.
=> I will bring some water in case
19. The policeman said to Mary, "Could you show me your driving license, please?"
=> The policeman told
20. He hasn't seen her for twelve years now.
=> He last
21. They acknowledge Hue as the World's Cultural Heritage.
=> Hue
22. The careful mechanic serviced our car last week.
=> The mechanic