—Why do you look so puzzled?—Oh，I ________ over a most difficult maths problem.
#99720
A
thought
B
have thought
C
am thinking
D
think
推荐题目
. ------Don’t put the waste on the ground. ------Oh, I’m very sorry. I ____ the dustbin there.
#103748
A
don’t see
B
isn’t seeing
C
didn’t see
D
haven’t seen
(2013·江苏，21)Generally，students' inner motivation with high expectations from others________essential to their development.
#99734
A
is
B
are
C
was
D
were
The past two years ________ a sharp rise in oil price, which adds to the burden of auto transportation industry.
#101865
A
witnessed
B
has witnessed
C
is witnessing
D
witnesses
Then over dinner,Franklin mentions that he well since he gave up smoking and Dr Candy,the local doctor,offers to write him a prescription for some medicine.
#103961
A
had not been sleeping
B
has not been sleeping
C
is not sleeping
D
was not sleeping
.In this experiment, they are woken up several times during the night, and asked to report what they＿＿＿＿.
#104486
A
had just been dreaming
B
are just dreaming
C
have just been dreaming
D
had just dreamt