Question

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

Answer 1

C

Whether---or·---表选择。问题的给出是为了决定是提高水平还是做同一水平的题。故选C。