50đ giải đúng đầy đủ nhất nha đầy đủ chi tiết nhất cần gấp giải thích nha

$Đáp$ $án$ + $giải$ $thích$:

`1`. `M`r. Nam has taught English for 20 years.

`-` `S` + started/began + toV/V-ing + ago/in,when....

`->` `S` + have/has + `V3` / `ed` + for..../since...

`2`. `S`he has never come to Viet Nam before.

`-` `T`his is the first time + `S` + have/has + `V3` / `ed`....

`->` `S` + have/has + not/never + `V3` / `ed` + before.

`3`. `I` haven't met her for 3 years.

`->` `C`ấu trúc: `S` + haven't/hasn't + `V3` / `ed` + for..../since....

`4`. `I` have never read such an interesting novel before.

`-` `T`his is the first time + `S` + have/has + `V3` / `ed`....

`->` `S` + have/has + not/never + `V3` / `ed` + before.

`5`. `I` have been to Hanoi twice.

`->` `C`ấu trúc: `S` + have/has + `VPII` + .....

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