Recently quite a lot of experts _____ that another law on wildlife protection ____ as soon as possible.
______ he referred to in his article was unknown to the general reader.
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.