As a student in Senior Three, I must work hard． ___________, I should take exercise to strengthen my body．

Our country will try to make greater progress in improving people's living conditions，________low­income families.

In it were photos of all the actors of our show, _____ signed by each performer.

Noise is unpleasant, _____ when you are trying to sleep．

The students are ___ young people between the age of sixteen and twenty.