Find a mistake of each sentence by circling the letter A, B, C or D

Part 2. Find a mistake of each sentence by circling the letter A, B, C or D. 
1.  Did they bought some beautiful roses for her mother?
A. Did                      B. bought            C. roses                D. for
2. Are he finish his tests before going out yesterday?
  A. Are              B. finish            C. his               D. out
3.  At present, our class was doing a big project on how to save energy in our school.
A. on             B. was        C. in                  D. save
4. Nowadays, people in Africa is not using energy from natural gas.
A. using               B. in         C. from                  D. is
5. Can yours sister perform Dutch folk dances? – Yes, she can
A. yours        B. can        C. dances        D. perform