1. from -> since
has never been => Thì HTHT => Dùng "since" để chỉ mốc thời gian
2. have -> has
-> CN là Mary (số ít) => Dùng "has +V_pII"
3. fly -> flying
-> flying object: vật thể bay
4. make -> to make
-> how to V: làm thế nào để ...
5. it is -> it was
-> "a few years ago" => Thì QKĐ
#Chii
#Team: Natural Science Boss