They've kept up a friendship with the teacher whom they were at school _____ twenty years ago. 
#28347
A
with
B
about
C
since
D
till
推荐题目
The discovery was made_______, which we hadn’t expected .
#26723
A
on purpose
B
at present
C
in advance
D
by accident
Sam always pronounces my name wrong.  Do you think he does it ______ ? 
#25559
A
on purpose
B
at present
C
at an end
D
right away
To reach Africa, we flew      high mountains,      deep valleys and     great deserts(沙漠).
#26301
A
on, across, though
B
over, through, through
C
over, through, across
D
on, in, across