All of the following are our school rules except “”.

They worked hard_____they finished theirwork ahead of time.

Your shoes smell terrible, Eric! —I’m sorry, I’ll____ and wash them at once.

Would you like to talk with your father or mother, Liu Mei— We don’t have the same topic(话题).

It was at four o’clock in the afternoon____ he and his grandpa reached the museum in Guanghan