For or Since

Mr. Johnson has worked for this company ................... 1980.

Kate hasn't eaten anything .......... six hours.

Peter has read eleven books ............... last weekend.

Jason and Clara have been friends ............. more than 10 years.

Cindy has driven her car ............... only five months.

We haven't seen Mr. Parker .................. this morning.

David hasn't telephoned .................. he left school at three o'clock.

The singer has sung seven songs ............... the concert began.

George has been a teacher ........... six years

John and Mary have been married .................. they finished university.