The professor had no sooner finished his speech ________ the students started cheering.
To battle world hunger, the great scientist once traveled to many places where populations _______ faster than crop production at that time.
The government won’t have the public officials ___ asking for gifts or money from people.
Unfortunately, some natural signs which might have helped more people survive the earthquake were ________.
. ___________ the extreme levels of air pollution, city authorities have started to take measures to quickly reduce pollution levels and protect city dwellers.
Whenever I read the old letters, _____ was fairly often, sweet memories warmed my heart.