Làm giúp mình câu 13 đến câu 20

$\text{13.The last time he wrote to me two months ago.}$

$\text{14. It is two years ago since I last went to London.}$

$\text{15. My father hasn't seen his brother for nearly twenty years.}$

$\text{16. I haven't sung this song for many years.}$

$\text{17. How long is it since you stop use your Facebook?}$

$\text{18. How long has Mary started listening to classical music?}$

$\text{19. When did you last watched action movie?}$

$\text{20. This is the first time Minh corresponded with his classmate.}$