The best way to prevent the air polluting _____ , but the sky is still not clear

_________ thing for us is studying hard.

You ________ believe how wonderful Van Gogh’s “Sunflowers” is until you ________ it with your own eyes

I won’t forget my teacher because she ________so kind to me since I came to this school

Varieties of household goods are sold here, ________from babies’ toys to old men’s walking sticks.