Questions and exercises  are given by the computer, which decides ______ to move the students ahead, review an easier level, ____ give more work on the same level.

   A. either, or    B. both, and    .C. whether, or     D. not only, but also

Questions and exercises  are given by the computer, which decides ______ to move the students ahead, review an easier level, ____ give more work on the same level.

   A. either, or    B. both, and    .C. whether, or     D. not only, but also

Questions and exercises  are given by the computer, which decides ______ to move the students ahead, review an easier level, ____ give more work on the same level.

A. either, or    B. both, and    .C. whether, or     D. not only, but also

Questions and exercises  are given by the computer, which decides ______ to move the students ahead, review an easier level, ____ give more work on the same level.

1. A.
   either, or
2. B.
   both, and .
3. C.
   whether, or
4. D.
   not only, but also