`\color{#145277}{N}\color{#246483}{a}\color{#34768F} {e}\color{#44889B}{u}\color{#539AA7}{n}`

`@` For `+` quãng thời gian : trong khoảng (for a month, for a long time)

`@` Since `+` mốc thời gian : từ khi (since `2006`, since `2008`)

`(+):` S + have/ has + V3/ed

`(-):` S + have/ has + not + V3/ed

`(?):` Have/ Has + S + V3 `?`

       WH-word + have/ has + S (not) + V3 `?`

`->` S = I/ We/ You/ They + have

`->` S = He/ She/ It + has 

`--------------`

`7.` `B`

`-` Phủ định : no one

`@` S `+` last `+` V2/ed `+` O + (time)

`->` S `+` haven't `/` hasn't `+` V3/ed `+` O `+` for `+` time

`8.` `B`

`-` HTHTTD : S `+` have `/` has `+` been `+` V_ing

`9.` `A`

`-` After `+` QKHT (had `+` V3/ed) : nói về nguyên nhân `1` sự việc xảy ra trong QK

`10.` `C`

`@` S `+` started `/` began `+` V_ing `/` to-V `+` O `+` time

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

`11.` `B`

`@` It is `+` time `+` since `+` S `+` last `+` V2/ed `+` O

`->` S `+` haven't `/` hasn't `+` V3/ed `+` O `+` for `+` time

`12.` `C`

`13.` `C`

`-` used to `+` V : đã từng làm gì

`14.` `B`

`-` have never : mang nghĩa phủ định