It shows what has happened the forests of the USA in the last 350 years.[ ]

It was not until the beginning of the twentieth century________to explore space.

So you were in the supermarket __________ you heard a strange sound, right?—That’s true. I ran out as quickly as possible.

I’m thirsty, Steven. Please pass ____ a bottle of water.

Where are his books? _________ on his bed.