These natural disasters have warned us that everyone should start to protect the_________ immediately.

There’s no      from my bedroom window except for some factory chimneys.

— Don’ t be so naughty! Be your _____．— Got it．

In order to increase the______ of the farm______, our government offers a lot of money to the peasants every year.   

I must have been a great _____ to my parents in those hard days, for I never failed to live up to their expectations.