________ all the homework assigned by the school, the students have to work at it till midnight.
Now an increasing number of middle school students go abroad for further study at their own ________, trying hard to realize their dreams.
Darwin counted 225 flowering plants, ________ he collected and brought home 193.
The government has taken some measures to reconstruct the earthquake-hit areas, but it must be some time ________ everything returns to normal.
________ twice a year, whether it is a car or a bus or a truck, is the rule that every driver must obey in this city.
We agreed to accept ________ they thought was the best professor in the college.