9. Lan hasn't written to Maryam for a month.
-> It's one month since Lan last wrote to Maryam.
*Công thức: Chuyển đổi câu HTHT <-> QKĐ:
- S + have/has (not) + V_ed/V_pII + O + for + time
= It's + time + since + S + last + V_ed/V_pI + O.
#Chii
#Tired of studying well