____I feel pity on earthquake victims in Sichuan, I can’t really do very much to help them but contribute my pocket money.
_____ is the population of your country?
Please say "Hi" to Bob ______ me.
After we walked ______ the forest, and ______ a river, we arrived at that small village.
We were about to leave the classroom _____ it began to rain.
Three students in ten will go and _____ to stay in the classroom.