`8`.It is `3` months since they last talked to each other

`->` It is + time / in timeline + since + S + last + Ved / V2

`=>` Đã bao lâu từ khi lần cuối làm gì

`9`.The woman has lived in Da Nang city since she was `8`

`->` Thì HTHT : S + have / has + VpII 

`=>` He , She , It `+` has

`->` Since + Timeline : Từ khi nào

`10`.He started to teach the children in that remote village `5` months ago

`->` S + started / began + V-ing / to V

`=>` Bắt đầu làm gì

`\text{# TF}`

8 It is three months since they last talked to each other.

`-` It + be + thời gian + since + S + last + V(qk) + O: Đã là bao lâu kể từ khi ai đó lần cuối làm gì.

9 The woman has lived in Da Nang City since she was 8.

`-` since + mốc time: DHNB HTHT.

`=>` S + have/has + Vpp + O.

10 He started teaching the children in that remote villages five months ago.

`-` started/began + Ving : bắt đầu làm gì.