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.
#80118
A
either, or
B
both, and .
C
whether, or
D
not only, but also
推荐题目
I doubted her honesty________I met her.
#30062
A
first time
B
for the first time
C
the first time
D
by the first time
Exactly______ the potato was introduced into Europe is uncertain, but it was probably around 1565.
#30010
A
whether
B
why
C
when
D
how
A good friend of mine from I was born showed up at my home right before I left for Beijing．
#80680
A
how
B
whom
C
when
D
which