Lesson 12. 
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* Problem 1.
1. big - small
2. new - old
3. short - long
4. good - bad
5. cold - hot
6. warm - cool

* Problem 2.
1. This is a new pan.
2. He is a tall boy.
3. She is a pretty girl.
4. He is an old man.
5. Tom has an old coin.

* Problem 3.
1. You have a good camera.
2. This flower is beautiful.
3. Do you like cold winter.

* Problem 4.
1. This is a small book.
   This book is small.
2. This is an old watch.
   This watch is old.
3. That is a big bird.
   That bird is big.

* Problem 5.
1. I know that man.
   I know that young man.
2. I don't have a camera.
   I don't have an old camera.

* Problem 6.
1. That is a tall building.
2. I have two white cats.