B1
1. Had Had / went
2. working
3. could
4. will offer
5. Will be
6. was reading / heard
B2
1. A
2. B
3. A
4. A
B3
1. My friend asked me why i liked learning English.
2. The flowers which you cut this morning are beautiful.
3. Would you mind if I sit next to you?.
4. If i were Ba, I wouldn't do silly things.
5. They suggest that we should go to school by public transport in order to save energy.