where is your boyfriend from? my boyfriend is british
your chinese teacher is chinese, what about your friend?
is this your friend?
is that chinese person your classmate?
who is your girlfriend? that american is my girlfriend

1. What country is your boyfriend from? My boyfriend is English.
2. Your Chinese teacher is Chinese, what about your friend?
3. Is this your friend?
4. Is that Chinese person your classmate?
5. Who is your girlfriend? That American is my girlfriend.

correct

1. Which country is yoru boyfriend from? My boyfriend is British.
2. Your Chinese teacher is Chinese, is she your friend?
3. Is this your friend?
4. Is that Chinese person your classmate?
5. Who is your girlfriend? That American person is my girlfriend. 

1. What country is your boyfriend from? My boyfriend is British. 

2. Your Chinese teacher is Chinese, how about your friend? 

3. Is this your friend?

4. Is that Chinese person your classmate? 

5. Who is your girlfriend? That American person is my girlfriend.

1. What nationality is your boyfriend? My boyfriend is English.
2. Your Chinese teacher is Chinese, what about your friend?
3. Is this your friend?
4. Is that Chinese person your classmate?
5. Who is your girlfriend? That American is my girlfriend

All are correct.

1. Where is your boyfriend from? My boyfriend is British.
2. Your Chinese teacher is Chinese, what about your friend? 
3. Is this your friend?
4.  Is that Chinese person your classmate?
5. Who is your girlfriend? This American person is my girlfriend.