5- I bought a picture. It was very valuable. (a relative word)
=> I bought a picture which was very valuable.
6-These shoes are of excellent quality. They are produced in that factory. (a relative word)
​=>These shoes whuich are produced in that factory are of excellent quality.
7- The highest building is on Nguyen the street. It was built in 2002. (a to infinitive)
​=>The highest building which was built in 2002 is on Nguyen the street.
8- Mary is the only girl. She always brings me joys. (a to infinitive )
​=>Mary who always brings me joys is the only girl.
9- The children are very nice. They live next door. (a participle)
​=>The children who live next door are very nice.
10- We stopped to swim in a small river. It looked very clean. (a participle)
​=>We stopped to swim in a small river which looked very clean.