Some people fear that ______ air pollution may bring about changes in ______ weather around the world. 

Some of the students think that English learning should start early, because little children have_____good memory, and they can learn many more words by_____heart.

I am­­____ of the class team at school and I am also ___ of the Senior High team.

For a long time they walked without saying _____ word. John was the first to break _____ silence.

As the most acute one in _______ history of all epidemics, the Spanish Flu had ______ tendency to strike the young and fit rather than the old.