Can someone please correct these Japanese exercises I found on the internet? [3]
(Exercise 3) Please render the follwing phrases in Japanese.

1, the car of my friend
Tomodachi no kuruma

2, the teacher of your school
Gakkou no sensei

3, the book of Japanese history
Nihongo no rekishi no hon

4, my friend's company
Tomodachi no kaisha

5, the house of our family
Watashi-tachi no kazoku no uchi

6, the language of his country
Kare no kuni no kotoba

Question

Can someone please correct these Japanese exercises I found on the internet? [3]
(Exercise 3)  Please render the follwing phrases in Japanese. 

1, the car of my friend
Tomodachi no kuruma

2, the teacher of your school 
Gakkou no sensei

3, the book of Japanese history
Nihongo no rekishi no hon

4, my friend's company
Tomodachi no kaisha

5, the house of our family 
Watashi-tachi no kazoku no uchi

6, the language of his country
Kare no kuni no kotoba

Answer

1, the car of my friend 
Tomodachi no kuruma 
↓
(watashi no) tomodachi no kuruma
NOTE: you can omit "watashi no" (=my) in conversations when it is obvious

2, the teacher of your school 
Gakkou no sensei 
↓
Anata no gakkou no sensei
(NOTE: we usually do not omit "anata no" (=your) )

3, the book of Japanese history 
Nihongo no rekishi no hon 
↓
Nihon no rekishi no hon

4, my friend's company 
Tomodachi no kaisha 
↓
(watashi no) tomodachi no kaisha
(NOTE: same as Q. 1)

5, the house of our family 
Watashi-tachi no kazoku no uchi      OK

6, the language of his country 
Kare no kuni no kotoba                  OK