[单项选择]We（　） our dinner when a policeman came to the door.
A. just had
B. have just had
C. just have had
D. had just had

[简答题]

Ah, blissful sleep, when we leave our daily toils behind and slip into mindless repose. Or do we (46) Two reports in Science, one involving rats and the other humans, suggest that during sleep our brains remain quite busy, furiously consolidating important memories that have accumulated during the day.
In the rat experiments, Matthew A. Wilson of the Massachusetts Institute of Technology and Bruce L. Mc Naughton of the University of Arizona inserted electrodes into the hippocampus, a region of the brain thought to be involved in spatial memory. As the rats learned to navigate a maze, their neurons fired in certain patterns corresponding to specific parts of the maze.
(47) For several nights after the rats’ maze exercises, their hippocampal neurons displayed similar firing patterns; the rats were apparently playing back their memories of running the maze. The major difference was that the firing was more rapid, as if the memories were being run

[单项选择]When we plan our vacation, mother often offers______suggestions.
[A] careful [B] practical [C] effective [D] acceptable

[填空题]It was rather late when we came out the cinema. 76. _____
We all knew that the last train will leave at 11:50. So 77. ______
we ran as quick as we could to the station. 78. ______
It was just a quarter past 11 that we arrived 79. ______
in the station, but the trains often leave a 80. ______
little lately and there was a train at 81. ______
the platform. However we got on. We waited 82. ______
for half an hour, and then we got out. We find a 83. ______
station worker and asking when the train was 84. ______
going to leave. "Tomorrow, six o’clock," he 85. ______
said to us.

[单项选择]Hardly （　） when the door suddenly closed.
A. they had arrived
B. they arrived
C. did they arrive
D. had they arrived

[填空题]When we hate our jobs, the trick is to ______.