The ________ on driving after drinking alcohol is being carried out all over the country, which is helpful to reduce traffic accidents.
______ in the novel, I didn’t notice what was happening.
I am sorry that I can not meet you at the railway station. I _______ Beijing by the time you come back from abroad.
The thief looked around every now and then _____ he knew he was being followed.
He insisted ______ alone in the mountain.
Xi’an was attacked by such a terrible smog _____ few residents had ever experienced before.