Помогите пожалуйста)Combine the two sentences. use the second sentence as an

Помогите пожалуйста)
Combine the two sentences. use the second sentence as an adjective clause.
1 The girl is happy. she won the race.
2 the student is from China . he sits next to me.
3 The students are from China. They sit in the front row.
4 we are studying sentences. they contain adjective clauses.
5 i am using a sentence. it contains an adjective clause.
6 algebra problems contain letters. they stand for unknown numbers.
7 the taxi driver was friendly. he took me to the airport.