_______ the rain falling so hard, it becomes more and more difficult to carry on the rescue work.
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.