The lack of money forced them to________their research.
In the face of danger, we need to stay ____. Only in this way can we come up with good solutions.
Yesterday we went to visit the farm ____ my father used to work for nearly ten years.
Every minute must be made full use of ____ our lessons, for the final examination is coming.
The foreigner does speak Chinese well, but of course not _____ we Chinese.
The reason _____ he refused to attend the meeting was that they didn’t give him an invitation earlier.