Living in the countryside is not expensive, and it isn't complex, __

4. Living in the countryside is not expensive, and it isn't complex, ...........................

A. so                           B. too                                     C. either                     D. neither

5. What have you learnt since you...........................here?

A. come                     B. is coming                          C. have come            D. came

6. This big building was built ...........................1980 and 1983.

A. since                      B. between                            C. from                       D. for