`1` I'm looking for some nice invitation cards which must come from recycle materials.

`-` ''some nice invitation cards'' là đồ vật .

`=>` Dùng ''which'' .

`2` We are having a clothes swap party where We can all get new outfits for free without harming the environment.

`-` ''a clothes swarp party'' là nơi chốn cũng như địa điểm.

`=>` Dùng ''where''.

`3` The local government wants to encourage people to use public bicycles in order to protect the environment.

`-` Clause `1` + in order to + clause : Mệnh đề lí do.

`-` encourage sb to V : khuyến khích ai làm gì.

`4` No land animal is faster than the cheetah.

`-` So sánh không bằng : No + N + be + adj-er + than + S.