I became a teacher in 1993. I _______ for 13 years by next summer.

1. A.
   has taught
2. B.
   will teach
3. C.
   has been teaching
4. D.
   will have been teaching

I became a teacher in 1993. I _______ for 13 years by next summer.

  A. has taught                 B. will teach   C. has been teaching      D. will have been teaching

I became a teacher in 1993. I _______ for 13 years by next summer.