`1`. Lan, who lives near my grandparent's house, is my classmate.

`2`. The young man, who is Ba's brother, is talking to our teacher.

`3`. We visited the monument which was built a hundred years ago.

`4`. The victims of the flood who were half-starved for many days need help.

`5`. The baby who was lifted and put down a hundred meters away by a tornado was still alive.

`6`. The weather forecast program which some people like to watch takes place at 8 p.m everyday.

`7`. Hoa’s parents, who buy a lot of candles and food, will use them in case the market is closed because of the hurricane

`8`. Mr Phong, who has been teaching in our school for ten years, is our geography teacher

`9`. Nam, who learns in our class, is very intelligent.

`10`. Minh, whom I have known since we were at school, is one of my best friends.

`11`. The new stadium, which can hold 120.000 people, will be opened next week.

`12`. My mother, who is an excellent cook, works as an engineer.

`13`. His book, which was published last year, became the best seller.

`14`. Neil Armstrong, who walked on the moon, lived in the USA.

* Cấu trúc:

- "which" thay cho vật đóng vai trò là chủ ngữ hoặc túc từ

- "who" đóng vai trò là chủ ngữ

- "whose" + N `->` chỉ sở hữu 

- "where" chỉ nơi chốn

* Dùng mệnh đề quan hệ không xác định khi:

- Có tên riêng, danh từ riêng

- Có tính từ sở hữu 

- Có đại từ chỉ định