—Where’s my cat, Bill? —There aren’t any cats here, ___________ there’s a little dog.

Learning to write is learning to think. You don’t know things clearly _______ you can write them down.

 Across from my home, ______ a shop which sells things from foreign countries.

---        can you see in the picture?        ---Some birds.

Earth is becoming more and more polluted. ______, people will move to Mars one day.