__________twice a year, whether it is a car or bus or a truck, is the rule that every driver must obey in this city.
Rather than _______ on a crowded bus, he always prefers________ a bicycle.
I can still remember ______ it was so long ago.
It was the first time that I __________ the night face to face.
To improve your spoken English, you’d better listen to the tape ______.
Ten minutes later,a bus ______ and everybody got on it.