`1.` Mrs Vanlencian has been living in Philippines since she was `8`.

`->` HTHTTD : S + has/have + been Ving

`2.` Linda regretted not having tried hard to help her classmates last winter.

`->` Regret + Ving : Hối hận

`->` Having PII để nhấn mạnh QK

`3.` 3D printing allows making three dimensional objects.

`->` Allow + Ving : Cho phép làm gì

`1` Mrs Valencian has been living in the Philippines since she was `8`.

`-` HTHTTD since QKĐ

`->` HTHTTD: S + have/has + been + V-ing

`->` QKĐ: S + V-ed/c2

`2` Linda regretted not trying hard to help her classmates last winter.

`-` S + regret + (not) + V-ing: hối hận (không) làm gì

`3` 3D printing allow making three dimensional objects.

`-` S + allow + V-ing: cho phép làm gì