Giúp mình với 1.Swimming in the river is dangerous. It is....... 2.they built this school 30 years ago. This school.......... 3.she said, "I am not hungry now. She said that.......

`1` It is dangerous to swim in the river.

`-` It's + adj + to V

`2` This school was built `30` years ago.

`-` Bị động QKĐ: S + was/were + Vp2 + (by O)

`3` She said that she wasn't hungry then.

`-` Câu tường thuật: S + said + (that) + S + V(lùi thì)

`-` HTĐ `->` QKĐ

`-` now `->` then

1 It is dangerous to swim in the river.

`-` It + be + adj + to V + O: Nó như thế nào khi làm gì.

2 This school was built 30 years ago.

`-` Bị động quá khứ đơn: S(pv) + was/were + Vpp + O.

3 She said that she was not hungry then.

`-` Gián tiếp tường thuật: S + said that + S + V + O.