Paul had to write a history paper, _____ he couldn’t find time to do it.
The train ______ at seven o’clock and you’d better get to the station by half past six.
--- What happened to you?--- I was lost in the strange city; _______, it began to rain heavily.
Things came ______ after that. And now he has ______ student in Nanjing University.
Flight attendants usually need to arrive at the airport ______ before their flight leaves.
--- Who are you waiting for?--- ______ us a lecture this afternoon.