II-
11.have->has
12.have depended->have to depend/depend
13.look->looking
14.improve->have improved
15.will leave->leaves
III-
16.He hasn't gone abroaf before
17.She has learnt French for 1 month
18.We have eaten since it started to rain
19.I haven't had my hair cut since I left home.
20.She hasn't talked to me for 5 months.
Chúc bạn học tốt nha ^^