Questions and exercises are given by the puter, 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
网友回答
C解析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。