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·---表選擇。問題的給出是為了決定是提高水平還是做同一水平的題。故選C。