Complete the sentences with the given words in their proper forms. (用括号中所给单词的适当形式完成下列句子。)

1. Our classroom is not as big as __________, but it's very clean. (they)

2. Many young people want to become cartoon __________ in the future. (artist)

3. The Smiths moved into their new house which is on the __________ floor. (twelve)

4. It is really __________ to raise the dogs because they can help humans to hunt. (wonder)

5. Body language is the __________ and most powerful language of all! (quiet)

6. Listen to the teachers __________ in class and many of your problems will go away. (careful)

7. Work today is very __________ from the way it was fifty or even twenty years ago. (difference)

8. The electric light is one of the greatest __________ in the world. (invent)