It was quite a long time _____I made it out what had happened.
The Town Hall ______ in the 1800’s was the most distinguished building at that time.
After a knock at the door, the child heard his mother’s voice ______ him.
Pop music is such an important part of society ______ it has even influenced our language.
With the help of high technology, more and more new substances ______ in the past years.
--- Guess what! I have got A for my term paper.--- Great! You ______ read widely and put a lot of work into it.